ESP migration in a pressure-cooker economy: 10 frameworks for doing it right, according to the experts

Profile photo of author Jax Connelly
Jax Connelly
30 min read
Customer data
January 24, 2023

Remember that scene in The Lion King, when Mufasa tells Simba their kingdom is “everything the light touches”?

Jen Brennan, director of digital marketing at full-service digital experience agency Northern Commerce, says that’s the best way to think about your brand’s email service provider (ESP).

“If you’re trying to achieve customer centricity and create positive customer journeys, your email marketing touches every part of your organization,” Brennan says.

From your IT team to your order fulfillment team to your customer success team and everyone in between, “every single one of them owns a piece of the customer journey,” Brennan emphasizes. “Everyone.”

More plainly, your business is only as good as your ESP. That includes your bottom line—and your profitability.

More plainly, your business is only as good as your ESP. That includes your bottom line—and your profitability.

At ecommerce businesses, Johnnie Regalado, director of engineering at Shopify-focused Tomorrow, encounters a lot of professionals who “tend to ignore email as an aspect of ecommerce work.”

On the surface, that makes sense. Compared to all the other mission-critical tasks you’re focused on in the midst of a historic economic downturn, taking a hard look at whether your ESP is accomplishing what you need it to accomplish might seem like a low priority.

In fact, the No. 1 reason brands don’t move forward with an ESP migration, says Justin Ragsdale, partner at full-service digital agency IM Digital, is fear. “The fear could be about any number of things, but often we keep coming back to the same thing—‘I’m using this, it’s working, I don’t want to change anything while I have a lot of irons in the fire,’” he explains.

But if anything, the pressure-cooker state of the economy is exactly why it might be the perfect time to re-evaluate your ESP options.

After all, your email and SMS lists are the only thing on the internet you truly own. Everything else, you’re temporarily renting. In 2023 and beyond, building strong relationships with loyal customers will depend largely on your ability to communicate with them in a way that makes them feel seen, heard, and valued.

Your email and SMS lists—as well as how you collect, organize, and use your customer data—is where that work starts.

You’re looking for the tools that unlock more.
Johnnie Regalado
Director of engineering, Tomorrow

“You’re looking for the tools that unlock more,” Regalado points out. “You don’t want to manually run a sync of the product catalog from the ecommerce site, or the ERP to the ESP, every day. You want all that stuff to be dealt with so you can just focus on creating and sending the best emails.”

So, is your current ESP delivering, or is it time to upgrade to a marketing platform that empowers you to, in Regalado’s words, “unlock more”?

We know those aren’t necessarily easy questions to answer. Here, we walk you through several mental frameworks to help you determine if ESP migration is really right for your business—and, if it is, what ducks you’ll need to get in a row before you begin.

10 reasons to switch ESPs: weak vs. strong motivations

Businesses of all sizes have plenty of reasons to switch ESPs. But not all reasons are created equal.

Look for your own motivations on this list of 10 expert-cited reasons businesses switch ESPs—do they fall in the weak bucket, or the strong?

1. Weak: You’re on the hunt for the lowest price

Today, Northern works with mid-market to enterprise clients on everything from development to marketing to performance creative. But the agency’s email and owned marketing solutions “cut our teeth,” Brennan says, migrating small to midsize businesses from Mailchimp to Klaviyo.

Lately, many of the clients Northern meets with are—understandably—“very price-sensitive,” Brennan points out. “Obviously with what’s going on in the economy right now, price sensitivity is at a higher level than it was even a year ago.”

But switching for price, Brennan says, “is one of the weakest reasons I hear come across the board.”

Switching for price is one of the weakest reasons I hear come across the board.
Jen Brennan
Director of digital marketing, Northern Commerce

Why? Because it turns into one of Brennan’s biggest pet peeves: “treating marketing like a line item on your balance sheet.”

If you’re thinking about ESP migration, an important first step is “switching that mentality of not just being around price point,” says Brennan, who recommends kicking off that process by asking questions like:

  • What is our monthly cost?
  • What is our annual contract?
  • What does all of that represent?

2. Strong: You’re re-evaluating total cost of ownership

Compared to price, total cost of ownership can be “hard to wrap your mind around,” Ragsdale says. “Because yeah, you have your licensing fees, you have your use fees, but what about all the headaches you have or don’t have? How do you price that out?”

That might mean the time you spend waiting for support you never get, or it might mean the time you spend working with a newly hired CSM who “has no idea how to use this proprietary technology, and they just send you support articles you already read,” Ragsdale explains. “How do you quantify the cost of those types of intangibles?”

Especially at the top of 2023, when the “macroeconomic situation is not looking good for a lot of businesses,” Ragsdale says, “a platform might be more expensive, or it might be a little bit cheaper, or it might be the same. You have to go into this thinking about, how do we cut costs? How do we do more with less? That’s the key factor here.”

“If you’re spending more on the platform but you’re making more money on it,” Brennan agrees, “then that ROI is still an ROI-positive relationship.”

3. Weak: You’re reacting, not responding, to a negative experience

Brennan’s also not a huge fan of any motivation for migration “that’s very reactive.”

“That could be a multitude of things,” Brennan says, “but if you’re coming at this conversation because you had one poor user experience—something didn’t deploy or something didn’t fire the right way and now you’re just mad and you want to leave—don’t do that.”

Don’t rage quit a platform.
Jen Brennan
Director of digital marketing, Northern Commerce

In other words, “don’t rage quit a platform,” Brennan advises, laughing. “Don’t go into things reactively, because especially when we’re talking about ESPs, there’s so much feature functionality baked into these platforms that some of them are going to work for you and some of them aren’t.”

“If you’re not being cognizant of what your real values and goals and pain points are,” Brennan continues, “you may end up making a reactive decision that’s not a good one.”

That’s especially dangerous if you’re considering a platform that has an annual contract, Brennan cautions: “Now you’re locked into something that may not fit your needs.”

4. Strong: You can’t accomplish what you need to accomplish

Of course, there’s rage quitting, and there’s valid frustration. If you have a solid understanding of what you’re trying to get out of your ESP and your current platform simply isn’t delivering, it might be time to start seriously thinking about ESP migration.

“A lot of brands switch because of tool-level limitations—you can’t do this or you can’t do that,” points out Regalado, who oversees development for large to enterprise client implementations at Tomorrow. “And they’re just kind of tired of that. It’s just a pattern of, ‘Ugh—we can’t get this thing done.’”

A lot of brands switch because of tool-level limitations—you can’t do this or you can’t do that.
Johnnie Regalado
Director of engineering, Tomorrow

Must-have features in a new ESP might include:

  • Sophisticated flows
  • Powerful segmentation + custom events
  • Real-time customer data updates
  • One-click personalization
  • Easy template design
  • Omnichannel capabilities (ie SMS, email, social, push)
  • Insights into what messages are resonating + how your peers are doing
  • Predictive analytics
  • Built for ecommerce
  • Migration support documentation

This is actually the first thing Tomorrow tries to understand during the discovery phase with a client: “what level of maturity a brand is at with their email marketing,” Regalado says.

For example, “are they at a level where they have campaigns around transaction follow-ups? Abandoned cart, post-purchase, product recommendations, back-in-stock—all these revenue-driving pieces that are going to be really tightly tied to their ecommerce site and be really dependent on things like product inventory or catalog?”

If Tomorrow identifies a sophisticated email program, “that evaluation immediately shows us there’s a need” for a stronger ESP, Regalado explains.

The need may also become clear for an “old-school brand that has been doing old-school business for a long time,” Ragsdale says—perhaps all their email marketing strategy entails, for example, is sending one monthly loyalty email to a bulk list of subscribers.

Many of the large to enterprise businesses IM Digital works with fit this profile, Ragsdale explains: “They’re growing as a digital DTC business, and they’re ready to go through a digital transformation and adopt more modern technology.”

We need to revolutionize the way you communicate with customers.
Justin Ragsdale
Partner, IM Digital

In this scenario, IM Digital’s goal is to “stop the bleeding,” Ragsdale says. “We need to revolutionize the way you communicate with customers. Let’s get you onto something you can use, let’s double your ROI, let’s cut your campaign time in half, and let’s show you how easy it is to do it.”

An ESP like Klaviyo, Ragsdale says, “is really the cornerstone” of that transformation. “Klaviyo is the best, most effective platform for these types of companies that are trying to make that switch, in tandem with so many other aspects of their business—how they’re manufacturing, how they’re warehousing, how they’re fulfilling orders, how they’re treating customers, their customer service, their advertising, and their SEO.”

5. Strong: You need an ESP that will scale with your business

Brennan calls it the “flood pant stage”: when growing businesses “get stuck in this in-between which oftentimes forces them to fall into very stagnant solutions.”

For “anybody that’s coming off a Mailchimp-type of environment, what you can do there from an analytics and customer insight perspective works for a lot of small businesses,” Brennan says. “But when you get to that mid-market point, you’ve outgrown what that customer data can really do for you. You don’t have another option, so you’re forced to use Excel spreadsheets, or some other awful, manual, clunky solution to make it happen.”

So where does that threshold lie? It differs from business to business, but “the trigger could be something as simple as how big your email list size has gotten,” Brennan explains.

Once you get above about 50K subscribers, Brennan says, “that’s when the pain points start to show up. You go from the ability to send based on one lump sum group, into OK, now you’ve got X many people as a subscriber and they’ve got various different user behaviors and various different preferences, and how are you able to slice that up?”

An ESP that doesn’t streamline efficient, sophisticated options for segmentation and behavioral targeting will inevitably fall short.

In that scenario, an ESP that doesn’t streamline efficient, sophisticated options for segmentation and behavioral targeting will inevitably fall short.

“What amount of information do you know about your customers that is living in your marketing platform that you could use for good? If you don’t see it or you have to pull it from a clunky process, you’re going to miss things, you’ll leave money on the table, and you won’t be delivering the most optimal customer experience,” Brennan says.

Or maybe you’re not growing yet, but you’re poised to over the next 3-5 years—consider how your business needs will evolve as you scale. A marketing platform migration is a serious effort. It’s not a business process you want to set in motion only to end up with a stop-gap solution that you’ll have to replace again this time next year.

Ultimately, “it’s really about trying to find what works beyond minimum viable product,” Brennan says. “‘Functional’ is fine, but it’s not necessarily allowing you to do more.”

‘Functional’ is fine, but it’s not necessarily allowing you to do more.
Jen Brennan
Director of digital marketing, Northern Commerce

6. Weak: You’re going big for big’s sake

Of course, overbuying is just as big a risk as underbuying, experts agree. “Sometimes when you’re in that flood pant stage, you end up signing up for something that’s just way too much—it’s overkill,” Brennan points out.

Then, “you don’t know how to set it up, you don’t know how to adopt it, and you have people working in it who don’t really know what they’re doing with it,” Ragsdale explains. “Now you’re paying lots of money for this technology that’s poorly integrated, you only adopt 10% of the feature set, and you have all these problems.”

You’re paying lots of money for this technology that’s poorly integrated, you only adopt 10% of the feature set, and you have all these problems.
Justin Ragsdale
Partner, IM Digital

At that point, the sunk cost fallacy makes it harder to leave—after investing so much time and money, it might feel like you’re stuck there, even if you’re getting less return.

Don’t jump into an expensive platform with a long list of bells and whistles if it’s going to be impossible for your team to actually use. “You might need a Salesforce Marketing Cloud or an Adobe Marketo, but you might not,” Brennan says. “You might be able to make it work on your current platform.”

How? Understand what you need your ESP to help you accomplish at a big-picture level, and then “consider your must-haves and your nice-to-haves,” Brennan suggests. “Bucket things into those primary- and secondary-type needs.”

“It’s about making sure you’re not ending up in an ocean,” Brennan adds, “when you could comfortably stay in Lake Michigan.”

It’s about making sure you’re not ending up in an ocean, when you could comfortably stay in Lake Michigan.
Jen Brennan
Director of digital marketing, Northern Commerce

7. Weak: You believe in magic

The most frustrating motivation Ragsdale encounters for ESP migration is the belief that the new platform will automatically and immediately solve a complicated problem.

“‘I bought this and it’s going to make me more ROI right away, or it’s going to get me better deliverability’—well, it’s just a tool,” Ragsdale points out. “The new ESP isn’t going to do it for you.”

If your new ESP results in immediate gains in open or click-through rates, for example, it’s likely because of something you’re doing smarter in the new environment—not because of some magic inherent to the new platform.

Nobody has the magic bullet.
Justin Ragsdale
Partner, IM Digital

“Nobody has the magic bullet,” Ragsdale says. “You still need to plan, you still need to do your due diligence, and you still need to hold yourself accountable. Otherwise, it’s not going to work.”

8. Strong: You believe in efficiency

That said, though, some ESPs make the necessary human effort a little easier on you and your team.

“A lot of marketing teams need to be able to function daily without needing to call on a developer or lean on an agency partner they may or may not have,” Brennan explains. “If we migrate someone to a new ESP and they can’t deploy a simple campaign without needing us for support, that’s a huge miss.”

“One of the main things we do is try and evaluate the brand’s actual capacity to own something like this,” Regalado agrees. “A lot of times, yes, you could build any of the stuff that happens in an ESP custom. But the level of overhead from actually managing that gets bigger and bigger.”

A lot of times, yes, you could build any of the stuff that happens in an ESP custom. But the level of overhead from actually managing that gets bigger and bigger.
Johnnie Regalado
Director of engineering, Tomorrow

Remember, you’re looking for something that can “unlock more”—and according to Ragsdale, usability is actually one of the “key benefits” of switching to Klaviyo.

“The No. 1 problem I’ve seen after doing this for many years is that people buy technology, they have a really good vision for what they want to do with it and how they want to use it, but when they get down to brass tacks, there’s so many other things they need to focus on that are mission-critical that they put off adopting certain things that are not as important,” Ragsdale says.

The result: “They end up precluding the amount of ROI that they can capture using that technology,” Ragsdale explains. “They get it integrated, they get it set up, and they think, ‘Wow, that was painful—we’re going to build automations later, we’re going to build in personalization later, we’ll focus on these other things later.’ That happens a lot.”

“Those are the customers that we send over to Klaviyo,” adds Ragsdale, who notes that Klaviyo is IM Digital’s ESP recommendation for “basically 100%” of their clients.

Why? IM Digital can “get clients trained and have them adopt the feature set really quickly,” Ragsdale says. “Then, when it’s time to launch, email marketing is almost a non sequitur because you can put it almost on autopilot.”

OK—but when you’re exploring your ESP options, how do you evaluate something as intangible as ease of use? Ragsdale recommends asking questions like:

  • How am I going to use it?
  • How easily can I actually build?
  • How quickly can I get there?
  • How long will it take me to train people?
  • How much ROI will it get me?

“Every platform has features,” Ragsdale points out. “Every platform has subject line testing, every platform has personalization. It’s 2023. Every platform does everything. Everybody’s giving you a dog and pony show. You need to feel like, ‘OK, I got it—I’m going to be able to do this because it’s easy for me to learn and use and it integrates with my other technologies” [more on this in a moment].

“Typically the reason people are migrating to Shopify is to ease the day-to-day management and the uptime of their site and the speed to implement new features and changes,” Regalado adds. “We like to extend that philosophy out to the vendor selection, and from our point of view, Klaviyo meets that more than other ESPs.”

See how Klaviyo compares to other marketing platforms

9. Strong: You can’t access the integrations you need

Speaking of integrations: “That’s a whole other can of worms,” Brennan cautions. “Your ESP needs to integrate across multiple different tech stack conversations. Depending on the client, that could be either a short conversation or a long one.”

Maybe your business has brick and mortar plus ecommerce stores, a unique point of sale system, and loyalty and review programs, and you have grand plans to implement some seriously advanced email segmentation based on how and where in the customer journey people are buying.

“Being able to pull all of that together in a way that makes sense to them and works for them is a huge piece of the ESP conversation,” Brennan points out. “What ecommerce platforms are you using? What CRM system are you using? What order management system are you using? What needs to speak to your marketing platform to pull those customer journeys together?”

With an ESP like Klaviyo, we can usually get integrated and set up to all the major ecommerce platforms in a day.
Justin Ragsdale
Partner, IM Digital

With an ESP like Klaviyo, Ragsdale says, “we can usually get integrated and set up to all the major ecommerce platforms in a day”—because Klaviyo’s 300+ built-in data integrations work seamlessly with the tools you use to run your business.

10. Weak: You’re hoping to stick to the status quo

This is one of the biggest mistakes brands can make during ESP migration, Regalado says: “Trying to make their new platform do exactly what their old platform did.”

“That’s probably the most common mistake I see, and it’s also the most frustrating,” Regalado admits. “I’ve seen a lot of times this desire to rebuild something a previous ESP did without really understanding the why, or understanding how Klaviyo handles that particular use case differently or better.”

Here’s a technical example: “Some ESPs use front-end client-side javascript to detect newsletter sign-ups. But Klaviyo does not need to do that on Shopify. Klaviyo can integrate directly to Shopify’s back-end to check whether users have accepted marketing or not, so there’s no reason to do this front-end implementation,” Regalado explains.

Some clients, however, insist on it. “We could build the front-end implementation and connect it by API, but it would be a bunch of wasted development effort because that’s not the right, best-practice way to do it,” Regalado points out.

Things will change, and that’s OK. You’re going to need to embrace the new system. Learn the best way to use it, and use that as your new default approach.
Johnnie Regalado
Director of engineering, Tomorrow

If you’re going to migrate ESPs, then, “understand that you’re moving to something new that offers new features and different ways of working,” Regalado emphasizes. “Things will change, and that’s OK. You’re going to need to embrace the new system. Learn the best way to use it, and use that as your new default approach.”

How to evaluate your ESP options

Selecting a new marketing platform is a daunting business process—and a lot of it comes down to asking the right questions.

“All of the decision-making in terms of where you’re going, it’s almost the same process as renting or buying a home,” Brennan says. “You have to vet them, you have to check them out, maybe you’re doing some demos or free trials, but you really need to go through that whole process of trying these on.”

That process could take “3 months on its own to go through procurement, depending on who all needs to sign off on the decision,” Brennan warns. And with so many moving parts to consider, it’s hard to know where to start.

To help you get things moving in the right direction, Klaviyo created a free request for proposal template that includes 122 questions to ask of each marketing platform vendor you’re considering, across categories like email, SMS, data migration, and more. 

Klaviyo’s sample RFP template is a fully customizable and downloadable Google Sheet. Of course, not all of these questions will be applicable to your specific business needs, so take what’s useful, modify what’s partially useful, and leave the rest.

3 essential steps when preparing for ESP migration

Once you feel confident that replatforming is the right move for your business, “getting a roadmap together and having a game plan is critical to the successful adoption of any platform,” Ragsdale says.

Here are 3 crucial ways to do your due diligence as you gear up for ESP migration:

1. Build your roster of stakeholders (it’s longer than you think)

The first thing Tomorrow does when proceeding with a marketing platform migration is “identifying the stakeholders and the owners of the work, both during the migration and afterwards,” Regalado says. “That means getting the teams together and talking about their pain points and what they’re hoping to achieve by migrating.”

The list of people who need to be involved with an ESP migration, experts agree, is almost always longer than you think. From internal teams to external agencies, here’s who you should think about looping in to the conversation:

Your internal roster

Across your organization, many team members may not think an ESP migration “will have anything to do with them,” Regalado cautions.

But “this is a pretty significant undertaking,” he says. “It’s important to identify internal stakeholders and timelines and make sure everybody who will be involved in the migration project is informed to the degree they need to be.”

To that end, Brennan recommends asking yourself who’s responsible for:

  • Ecommerce?
  • The on-page experience?
  • Content marketing?
  • Offline conversions?
  • Order fulfillment?
  • Development?
  • IT?
  • Loyalty?
  • Retention?
  • Customer service?
  • Social media?
  • Customer relationship management?
  • Programs considerable?
  • Reviews?
  • Creative?

And that list isn’t even exhaustive. As Brennan points out, “who all feeds into the email marketing ecosystem? And with all these different teams, what are their set of requirements?”

During and after the ESP migration, who’s doing what? Under what timelines? And what are the expected milestones?

Questions like this are exactly why Brennan recommends “almost treating your internal teams like personas as you’re going through these processes. Who are your internal personas, and who will impact and be impacted by the migration as part of their day to day?”

Who are your internal personas, and who will impact and be impacted by the migration as part of their day to day?
Jen Brennan
Director of digital marketing, Northern Commerce

The more preparation work you can do to understand and uncover the effect the ESP migration could have on different aspects of the business, “the more likely you’ll be successful, because you don’t end up introducing surprises to those other departments that could add complexity late in the migration,” Regalado explains.

Your external roster

Brennan is understandably biased, but she highly recommends teaming up with an agency that offers expert migration services. “I am an email marketer by trade and I’ve come through the ranks as this channel has evolved over the years, so I have done a lot of things on my own. But there’s no shame in getting help when you’re in doubt,” she says.

No matter how intelligent and capable your team is, “everybody has limitations,” Brennan points out. It might be a matter of sheer resourcing: “Maybe you have people who fully know how to do this, but they’re time-strapped because they have other big projects. So even if you can, it doesn’t mean you can, because you don’t have time.”

Or maybe your people know how to do it—just not “in a full, accurate, quality way,” Brennan says. “You might be able to do it scrappy, or you might be able to do some of it, but not knowing how to fully, completely do this from a technical perspective is definitely a reason to consider leaning on an agency partner that has a really hammered-down process for this.”

Especially when we’re talking about something as important as your owned marketing channels, you will lose business traction if you need to take extra time to get it done right.
Jen Brennan
Director of digital marketing, Northern Commerce

“Especially when we’re talking about something as important as your owned marketing channels,” Brennan adds, “you will lose business traction if you need to take extra time to get it done right.”

2. Give yourself plenty of time—at the right time

On that note: Time is an essential component of a successful marketing platform migration. “The more time, the better,” Brennan says. “If you have to work under tight deadlines, then that can be done, too—just not without a bit of risk.”

How long does an ESP migration take?

Not including evaluation of ESP options or any of the preparation work—which, remember, can take up to 3 months—the sweet spot for the technical portion of the migration, Brennan says, is at least 30 days. Ragsdale agrees 4-6 weeks is ideal.

Including prep work, start to finish, you’re probably looking at 60-90 days, total, “depending on the amount of data we’re talking about and whether you’re going with a shared vs. dedicated IP, because if it’s dedicated you need to consider the IP warming process,” Brennan says.

“IP warming” refers to the practice of sending small, infrequent amounts of email to your most engaged subscribers, then gradually increasing your send size and volume over time.

After migrating to a new ESP, warming your IP address is particularly important in establishing a good sender reputation, reducing the risk of being blocked or ending up in the spam folder, and ensuring “you don’t lose valuable deliverability ‘credit’ from your warm-up and ramp-up period, which will benefit your dedicated domain,” Brennan explains.

“I would hate to see a client lose out on an opportunity to run a campaign that they had planned longer than a migration, but if you don’t have the ability to hit your audience because you’re going through a warming process, then there goes that opportunity,” Brennan adds.

This is also why it’s never a great idea to migrate systems under the pressure of a hard cut-off date with your current ESP: You want a bit of overlap between the old ESP and the new.

It’s like the slow process of moving out where you still have some stuff at the old place, but you have a lot of stuff at the new place.
Jen Brennan
Director of digital marketing, Northern Commerce

“It’s like the slow process of moving out where you still have some stuff at the old place, but you have a lot of stuff at the new place,” Brennan explains. “If you’re going through a warming process, you’ll need to make sure you still have both environments so you don’t completely lose volume.”

If the stars align and you can make it happen in that “perfect timeframe,” Brennan says, “great. But if not, then it really just becomes, what is the minimum viable product? Think about your nice-to-haves vs. your need-to-haves so that at least your lights are on and you can fully get through the migration.”

“As much as you can orchestrate the timing to work in your best interest, and avoid having to cut corners and rush the process and lose revenue,” Brennan adds, “that’s really the primary goal.”

When’s the best time for an ESP migration?

Not the week before Black Friday, “but I’ve done it,” Brennan laughs. Beyond that, it depends completely on the seasonality of your brand’s peak promotion periods.

If your brand sells the most patio furniture during barbecue season, for example, don’t plan your ESP migration for May or June. If your brand moves a lot of jewelry leading up to Valentine’s Day, don’t plan your ESP migration for January or February.

Once you’ve identified your peak selling season, work backwards “at least a quarter, if I had to be demanding,” Brennan says. “Do it a quarter before you need it, because then you also have a quarter of learnings that you can benchmark yourself against.”

“Your automations have had more time to run, you’ve potentially been able to run some A/B tests, and you’ve been able to see how your forms are performing from a conversion perspective, rather than getting those learnings at the same time as you’re trying to capitalize on as many conversions as possible,” Brennan explains.

Regalado also points out that completing a marketing platform migration around a month ahead of peak selling season can not only “give you the confidence you need to get things up and running, but also help you drive more traffic and see more ROI on that effort as quickly as possible.”

“Having the least amount of interruption is what’s most important,” Brennan summarizes. “Think about your customer experience, think about your overall promotion plans and when your business makes the most of its money in the year, and try to have your migration done before then.”

3. Audit, audit, clean, audit

Formal audits during the marketing platform migration preparation process can help set the stage for higher ROI, and might include any of the following:

An “integrations inventory”

Integration is “always the most difficult part” of an ESP migration, Ragsdale says. “You have to do your due diligence and figure out where you need to get data from, what data sources you can get into the new ESP without a custom integration, and what data sources you need to build a custom integration for.”

You have to do your due diligence.
Justin Ragsdale
Partner, IM Digital

Brennan agrees it’s crucial to “do a bit of an inventory” in this area. “What else is going to need to be able to talk to your marketing platform? What are the available native integrations with the new ESP? If there’s not a native integration, then we get back into the qualification of that need vs. want, because if it’s custom, it’s going to take longer,” she explains.

“When it’s Klaviyo, it makes us way happier, because there are so many native integrations,” Brennan adds.

But “the larger the company, the more complex the integrations are going to be,” Ragsdale points out. “Before migration, you have to figure out how to merge all this data and make it work together to have a truly omnichannel experience for your customers.”

Ragsdale recommends “setting deadlines for yourself so that when you do adopt the new platform, you can get as much ROI as possible.”

Scrubbing your data

Once it’s clear where all your data is coming from, Brennan urges businesses to “have a hard conversation with themselves around their customer data”—and, if possible, scrub it before the ESP migration.

Skipping this step, she says, is the biggest mistake she sees businesses make when they’re preparing.

A marketing strategy is only as good as your data.
Jen Brennan
Director of digital marketing, Northern Commerce

“A marketing strategy is only as good as your data,” Brennan says—but often, that data is “messy, it’s outdated, it’s not clean, and it’s not overly hygienic.”

Here, ask yourself:

  • Is our data optimized?
  • Does it give us a holistic view of the customer?
  • Is all of it useful?
  • Do we need to change the data layout on our new ESP?
  • Are there opportunities for improving our segmentation logic?

Northern often finds that “merchants collect a lot of fluff or even junk data that simply isn’t relevant or useful,” says Brennan, who recalls one instance where a brand’s CRM profiles included a “mustache count” from a short-term Movember contest they’d run 10 years prior.

Migrating data like this, which no longer holds business value today, “hinders the merchant’s ability to create scalable customer strategies and journeys,” Brennan explains.

Rather than “bringing over a pile of custom profile data you won’t use,” Brennan suggests, “audit the must-haves and nice-to-haves of your customer data. What really needs to live in your new marketing platform?”

Cleaning your lists

Similarly, understanding your engagement metrics and taking steps to optimize the general health of your actual emailable profiles “is a really big piece of preparing for a migration,” Brennan says.

The reason for this is simple: You don’t want to replicate problems from your old ESP. “As part of that technical due diligence, you want to make sure the lists you’re migrating are clean,” Ragsdale explains. “If you have 800K email addresses but only 400K have opened an email in the past 24 months, you can only consider a fraction of the full list to be active.”

“Depending on the regions you’re in, obviously compliance is a major consideration,” Brennan points out. “When we’re talking about IP warming and all of that, you want to avoid getting yourself into any sender reputation issues right out of the gate because you’re sending to a dormant, unengaged audience.”

Enter: “your traditional list cleaning exercise,” Brennan says. “Scrub your account of disengaged or otherwise invalid email contacts.”

Documenting your metrics

If you aren’t tracking metrics in your current ESP, you’ll have no way of knowing whether things are improving after the switch.

At the channel level, experts recommend paying attention to:

  • Subscribes/unsubscribes
  • Open rates
  • Email-attributed traffic
  • Orders from email
  • Email-attributed revenue
  • Conversion rate
  • Revenue per recipient

ESP migration might reap less tangible migration benefits, too, like the ability to accomplish things you weren’t able to do before, or easier, more efficient workflows for your people—“a decline in the time you invest to get campaigns up and running, or the number of escalated and critical issues related to email,” Regalado suggests.

Still nervous? Lean on your new ESP’s support team for help

Whether or not you choose to work with an agency on your ESP migration, it’s a significant time, financial, and personnel investment.

It’ll go a lot smoother if your new marketing platform offers premium support you can lean on when you need it—not just during migration, but over the long haul.

Because they’re development-focused, the team at Tomorrow doesn’t consider themselves email implementation experts, Regalado says. “We always suggest clients pick a provider they feel they can trust that gives them that kind of support,” he explains.

We trust Klaviyo because they have the tools and the teams and the experience to actually support our clients in implementation.
Johnnie Regalado
Director of engineering, Tomorrow

“That’s a big part of why we recommend Klaviyo,” Regalado explains. “We trust Klaviyo because they have the tools and the teams and the experience to actually support our clients in implementation.”

Brennan says working with Klaviyo’s success teams has created serious time savings for her own team at Northern—resulting in more billable efficiencies for the agency’s clients.

“I always tell my team, ‘Don’t take 20 minutes to try to figure it out yourself if you can just get on with support for 5,’” she says. “As much as we’re an elite partner, we don’t know everything. We know about a lot, and we know a lot about Klaviyo. But we access the Klaviyo customer success team when we need to.”

“The support system Klaviyo has created has optimized their specific clients for success,” Ragsdale agrees. “That’s evident in the customer success program, that’s evident in the onboarding processes, that’s evident in the pricing model, and that’s evident in the amount of investment Klaviyo has spent in building that partner ecosystem to support their clients.”

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Jax Connelly
Jax Connelly
Lead editor
Jax Connelly (they/she) brings 15 years of editorial experience to their role as lead editor at Klaviyo. She started her career doing SEO at a small digital ad agency and spent most of her twenties managing a financial magazine for a trade association based in Washington, DC. Most recently, they studied and taught writing at Columbia College Chicago during the peak years of the pandemic. Outside of her day job, Jax is an award-winning creative writer who has received honors including 4 Notables in the Best American Essays series, contest awards from publications like Nowhere Magazine and Prairie Schooner, and a residency from the Ragdale Foundation. Jax lives in Chicago, a block away from Lake Michigan.

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