New Approaches for Building a Healthy and Growing Email List


Data is at the heart of everything we do in email marketing, whether we're building relationships or selling. A healthy and growing database is your most important factor to succeed in every aspect of email.

Building a healthy base and growing that base are two separate but related functions. Although you can't have one without the other, you need different strategies to achieve the goals of both a healthy email list and a growing list.

I believe this so strongly that I devoted one episode of my company's webinar series, "Email & More," to the twin topics of email list health and growth, besides making it the focus of this Only Influencers post.

What's a 'healthy' database?

This seems like one of the most basic questions in email marketing, but the answers are trickier than you think.

To me, "healthy" means you have few deliverability issues and regular measurable engagement. The subscribers on your list want to be there. They open, click and convert regularly.

I discovered while working with a client that most of its spam complaints came from its welcome programme. You know – the point in the email lifecycle when subscribers are supposed to be the most engaged. That's scary!

As it turned out, this client was working with acquisition partners who got paid based on the quantity of addresses delivered, not the quality. You don't build a healthy database that way.

During our webinar, Guy Hanson, VP of customer engagement for Validity, said he and Steve Henderson, Head of Deliverability for Emarsys, came up with the "Three Cs" of a healthy database:

  • Compliant (It complies with permission/data laws)
  • Correct (It's accurate)
  • Complete (No missing fields)

"If you can tick all three boxes there you're probably going a fairly decent way towards having healthy data," he said.

How do you know if your email database is healthy?

Benchmarks are the conventional answer here, but they aren't the most reliable or accurate ways to measure your list's health. Looking at acquisition statistics, like the number of opt-ins every month, whilst an indicator of growth, also is not a reliable indicator of list health.

As Lea Palomba of IL3X points out on the webinar, you have to look at list decay – the number of opt-ins who end up churning, whether by unsubscribing, bouncing, going inactive or getting removed because of spam complaints.

As marketers we have many KPIs that not only assess the health of our email list but also the health and vitality of our email programmes overall. Fact is, it’s hard to have a healthy list if your program isn't actually giving your subscribers the results that they want.

Marketers often base list health diagnoses on positive metrics, such as opt-ins, opens, clicks and conversions. Although they're clearly useful in many ways and necessary metrics to measure, Alice Cornell of points out in the webinar that negative metrics like unsubscribes, bounces and spam complaints can be just as illuminating.

Just a small increase in one negative metric, like a surprise uptick in spam complaints, can send your list health plummeting. Monitoring this can give you insights to your programme’s content, offer and segmentation (or lack of) and reduce the chance of future deliverability problems.

Keeping your list healthy, a petition website, had explosive growth in 2020, matching the year's unprecedented social and political activity. These thousands of new users signing up to launch petitions could have overwhelmed the nonprofit organization, Alice said.

But had headed off potential problems ahead of time by adding quality controls at opt-in and segmenting its database by engagement so it could match message frequency with engagement.

"We realize that our data is really precious, and so we try to prevent invalid or

typo addresses or all of those addresses entering the database in the first place," she says. "Protecting your list at the first point is so important. You're preventing rubbish from coming in because we know 'rubbish in, rubbish out."

When analyzing list health, you must consider the nature of your business, not just a standard set of metrics or something some email expert said you had to do.

A nonprofit like would use different strategies from an ecommerce business, where one business blankets all of its subscribers regularly regardless of engagement, and another drops anyone who hasn't opened or clicked in 90 days.

Both of these extremes can result if you don't think about your business needs or if you read something that says "Cut your inactives off at 90 days!"

You must delve into your data to understand your lifecycle and, in turn, your inactives. At what point do they become inactive? Do newly inactive subscribers differ from long-term sleepers? At what point can you no longer revive them?

That's when you can set an automated campaign to trigger at a specific point in the subscriber's lifecycle with your brand. These work well – they allow you to message less frequently and not put your inbox placement at risk.

And, naturally, cleaning your list early and often is essential. It's not enough to just remove hard bounces, unsubscribes and spam complainers quickly.


What's a growing database?

I mentioned earlier that list health and list growth are separate but related concepts that overlap. The overlap happens because having a sick database (high unengaged rate, lots of spam complaints and bounces whenever you send) means you have to work harder than ever to grow your database. Because you have to not just add new blood but also replace the bad or dead addresses.

Suppose your boss told you to grow your email list by 10% in the next fiscal year. It's a tall order, but doable, you think. Until you start punching numbers into the calculator, and you realise that you probably need to grow it by 30% to 40% to replace the ones you lost to churn and then add 10% on top of them to achieve list growth.

3 opt-in sources you haven't used yet

A form on the homepage, even supplemented with an entry or exit pop-up form, is a first step for gaining a regular supply of fresh email addresses. But here are three that can yield subscribers who might never go anywhere near your homepage.

1. E-receipts

I agree with Guy, who said on our webinar that he likes emailed receipts, either as an additional contact or a replacement for a paper receipt. Consumers are becoming big fans, too. The DMA's 2021 Consumer Email Tracker found 59% of consumers said they like e-receipts.

"Especially since GDPR was implemented, e-receipts have been a Top 3 source of list acquisition," Guy says. "What's nice about it is we're seeing a profile associated with consumers who are willing to receive an e-receipt. "They are typically more likely to be an email power user and highly engaged with the email channel. Generally, they're more likely to be primed for loyalty."

2. "Send cart to email"

This tactic combines opt-in and abandoned-cart messages. It invites a shopper who has left items in the cart to enter an email address and then have the list of items sent to her in an email, along with an invitation to opt into the email programme.

This is especially handy for mobile users who don't want to complete the purchase right at that moment. Plus, it collects an email from a motivated shopper and keeps her connected to the cart.

3. Win the battle for homepage real estate

Your homepage opt-in form isn't your only source of first-party data like an email address. But it's still the one many marketers rely on. You'd never know it from the way most  homepages treat that form.

Preparing for GDPR: The State of Retail Email Subscribe Forms 2018, a Holistic Email Marketing/Pure360 2018 study, found 87% of fashion retailers tucked the opt-in form on the bottom half of the homepage.

Putting the form at the top gives your opt-in maximum exposure and opportunity for action. But anyone who has pleaded with the web team for a more prominent location knows that's easier said than done.

Another frustration: Email marketers don’t always have the final say over where the opt-in form goes, even though they are responsible for hitting their list-growth goals!

That's how the opt-in form ends up somewhere on the left or right rail of the homepage or even in the same tiny font size as the staff directory and the jobs list at the bottom of the homepage.

Many email marketers own that space the way the web team does. Further, while web forms generate 72% of all database signups, only 50% of the email teams have any say over form content, our report found.

Here are four solutions:

  1. Try to work with the web developer. Ask to have different locations for the opt-in built into A/B tests whenever the designers want to change the page layout. There's a good chance (based on previous tests I've conducted) that if conducted and measured properly, not only will you benefit from more subscribers, but also more conversions.
  1. Show the value email drives for your company, whether you measure it in sales, account creation, loyalty or other KPIs.
  1. Look beyond the homepage. Argue for greater prominence on interior pages, such as product pages, landing pages tied to search or social campaigns and other high-traffic destinations.
  1. Barter. A box of doughnuts or a catered lunch is a nice bribe. But look for areas where your email team could help out the web or other teams.

Final thoughts

Don't forget about the value exchange that occurs every time someone signs up for your email. It's an old but evergreen marketing concept that we should emphasize more.

A subscription process is a transaction. You made subscribers an offer, and they accepted it. You now need to deliver upon your promise, which is delivering value. Therefore, every email can be seen as being a transactional or customer-service based email.

How well do you keep your promises to your subscribers? It affects the health of your list because keeping your promise encourages subscribers to keep opening, clicking and converting. The payoff: You won't have to work as hard to replace lost subscribers and add new ones.

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Cover Photo by Daniel Öberg on Unsplash