The retention gap: Kate Barrett on email marketing that drives customer retention and long-term growth

Why do so many brands keep sending out a constant stream of offers and discounts while customers quietly drift away? You know that email marketing is capable of more than just generating clicks and driving short-term sales, don’t you? When built around customer needs, it helps strengthen relationships, encourages repeat purchases, and supports long-term business growth.

In this interview, Kate Barrett, founder and lead CRM strategist at eFocus Marketing and a bestselling author, shares how marketers can turn email into a strategic customer growth channel. 

You can watch the recording of her RARE 2026 session ‘The retention gap: Why your retention strategy isn’t retaining customers’, to explore her approach to closing the retention gap in more detail.

Key takeaways

1. Retention starts with understanding customers. Look beyond campaign metrics to identify changing behaviours, unmet needs, and early signs of declining loyalty.
2. Connected customer journeys drive better results. Align email campaigns, automations, and other channels around customer needs, and test with a clear purpose to make smarter decisions.
3. Make every communication count. Use AI and personalisation to improve customer experiences, strengthen relationships, and drive measurable business growth, not simply send more emails.

Kate Barrett is the founder and lead CRM strategist at eFocus Marketing and the author of the bestselling book E-telligence: Email marketing isn’t dead, the way you’re using it is. With over 20 years of experience in email marketing, CRM, and customer lifecycle strategy, she helps brands build stronger customer relationships and drive millions of pounds in commercial growth.

Through strategic consultancy, audits, training, and speaking, Kate helps marketing teams turn customer insights into more effective experiences and measurable business results. Her approach focuses on making complex challenges practical, helping teams understand what’s happening, why it matters, and what they can do to improve.

From campaign metrics to customer growth: Rethinking email’s strategic value

Stripo: You’ve spent more than 20 years working across email, CRM, and customer lifecycle strategy. What originally convinced you that email could create business value beyond short-term campaign performance, and what has changed most in the way you evaluate that value today?

Kate: For me, email’s value comes from its ability to support the whole customer relationship. You can take someone from their first interest in a brand through to making a decision, getting value from their purchase, and becoming a loyal customer and advocate.

That customer-first approach was central to me writing E-telligence. Email underpins so much of the wider marketing journey, but its potential depends on how intelligently you use it.

Today, I put much more emphasis on whether customers are progressing and whether the relationship is strengthening. Are they getting value? Are they returning? Are the gaps between purchases changing? Are we becoming more relevant to them?

You can have a healthy-looking campaign results dashboard, while particular customer segments are quietly drifting, and areas of potential momentum are sitting as unfulfilled opportunities. I want to understand what sits underneath the numbers, why, and the decisions we should make as a result. Then, we execute the best decisions across the email channel (and wider into SMS or WhatsApp, paid ad retargeting, and push notifications) to drive maximum results.

S: What separates organisations that genuinely treat email as a strategic customer-growth channel from those that still view it primarily as a campaign or promotional channel?

K: For me, it’s looking at where the planning starts.

If the first question is always, ‘What are we sending this week?’, the campaign calendar is probably driving the strategy. A more strategic team starts with the customer: Where are they in their journey, what do they need, and what is preventing them from progressing? (Then we can layer the BAU campaigns in to support this journey.)

That thinking needs to be carried through into objectives, resources, and reporting. Teams need time to investigate behaviour, review existing journeys, and apply what they learn. Otherwise, even very capable people get trapped in delivery mode.

It also requires collaboration beyond the email team. 

Acquisition sets expectations, and the product and service experience either meets them or doesn’t; CRM needs to connect those experiences.

You can see the difference when customer insight changes a business decision rather than simply producing another campaign brief.

Audit the entire customer journey and test to learn, not just to win

S: What are the most revealing questions you ask when auditing a mature email programme that already has plenty of campaigns, automations, and data?

K: One of my first questions is deceptively simple: Do you know exactly what a customer receives?

This includes communications from your ESP, eCommerce platform, CRM, service team, and any other system. The documented journey and the actual experience can be quite different.

Then, I want to know:

1. Where are customers progressing, and where are they getting stuck?
2. Which segments are giving us less attention or taking longer to purchase again?
3. What happens to the messaging when someone buys, returns a product, or has a problem?
4. What have customers and customer-facing teams told us?
5. Which decisions have changed because of our testing?
6. What would we stop sending if we had to justify every communication today?

In my keynote, I suggested mapping every message one segment receives across every channel over 30 days. It’s a very practical way to see whether the experience feels connected, where messages overlap, and where useful support is missing.

(Source: Kate Barrett presentation for RARE 2026)

S: You’ve argued that testing needs to be done strategically with purpose and vision. What does strategic testing look like in a mature CRM programme, and where do experienced teams still waste testing capacity?

K: Strategic testing starts with something meaningful that we need to understand.

For example, if customers are dropping out of your welcome onboarding journey, we might believe that asking them to make too many decisions at once creates unnecessary effort. That gives us a hypothesis: simplifying the first step will help more customers complete it and move forward.

We then design a reliable test, agree on success criteria before launch, and choose measures that match the change. A higher click rate is useful, but if the purpose is successful onboarding, we need to follow it through.

The other waste is failing to apply the learning. Recording that one version won is only the beginning. What have we learnt about this audience, where else might it apply, and what will we now do differently?

The retention gap: Why more emails and discounts don’t guarantee customer loyalty

S: Your RARE 2026 keynote was titled ‘The retention gap: Why your retention strategy isn’t retaining customers’. What prompted you to frame the problem this way? What are brands calling a retention strategy that doesn’t qualify as one?

K: The central point of the keynote was that customers you think are loyal may already be drifting before your dashboard makes it obvious.

A widening gap between purchases is written off as a quiet month. Messaging no longer reflects what someone needs. Offers become the only reason they respond. Individually, these changes can be easy to miss.

(Source: Kate Barrett presentation for RARE 2026)

Meanwhile, the business has a welcome series, abandoned basket emails, a loyalty programme, and a win-back flow, so it feels as though retention is covered. However, these activities may have very little connection to one another.

My Customer Drift™ Framework looks at 1. attention, 2. behaviour, 3. relevance, and 4. value to help diagnose that weakening. 

My Customer Momentum™ Framework then gives you five principles for making better decisions to drive forward movement: 1. Strengthen trust, 2. create value, 3. reduce cognitive effort, 4. increase relevance, and 5. enable progress.

The gap is in how those decisions connect across the customer experience.

S: What are the most common mistakes you see brands make when trying to improve retention? Where do these mistakes tend to surface?

K: Waiting too long is a big one. If your first meaningful intervention happens when a customer becomes ‘lapsed’, you’ve missed several earlier opportunities to help.

Another is treating the post-purchase stage as an admin exercise: order confirmation, delivery update, review request, and then another promotion. There is often much more we can do to help someone use a product or service successfully and feel confident about their purchase.

Look at the questions people ask customer service and the reasons they return products. These can tell you exactly what your post-purchase communications need to address.

The underlying mistake is assuming that the same behaviour always has the same explanation. We need to investigate this before deciding what to send.

S: Many companies respond to declining repeat purchases by increasing promotional frequency, discounts, or media spend. Where does this become counterproductive, and what should marketers investigate first?

K: It becomes counterproductive when we keep asking for another purchase without understanding why the customer hasn’t returned.

If they haven’t received value from the first purchase, another discount may do very little. If their experience was frustrating, more messages can add to that frustration. If they only respond to offers, we need to understand whether we are encouraging a pattern that steadily reduces margins.

I’d first look at the affected segments, their normal buying rhythm, what they purchased, and what happened afterwards. Have their needs changed? Is there a product or service issue? Are we asking them to replenish before they realistically need to?

I would also look at the balance between useful support and commercial asks in the emails. How often are we helping compared to asking them to spend?

An incentive can be the right decision. However, we should know what barriers it addresses and whether it creates additional profitable behaviour.

Building the business case for retention through connected, relevant customer experiences

S: How should marketers make the business case for deliberate CRM, retention, and lifecycle investment when acquisition is often more visible to senior leadership?

K: Give retention the same commercial discipline and visibility you give acquisition:

1. Start with a specific opportunity. How many first-time customers fail to make a second purchase within a relevant period? What could a realistic improvement be worth?
2. That creates a business case you can test. Start with a defined segment and intervention, and then use a suitable control group to understand the additional value it creates.
3. Reporting should include repeat-purchase behaviour, time to the next purchase, and customer value over time alongside revenue from relevant journeys. 
4. Attribution also deserves scrutiny: The channel receiving the final click may not tell the whole story of what influenced the purchase.

Better retention also helps the business get more value from the customers it has already acquired.

S: What does a genuinely connected lifecycle strategy look like? How should teams move beyond isolated journeys?

K: I’ve talked for a long time about the five broad lifecycle stages: acquisition, consideration, purchase and experience, loyalty, and reactivation. Their value is still in helping us understand how customers need change (at the top level).

At each point, people are trying to accomplish different things, asking different questions, and feeling different emotions. The communications should respond to this.

I’d start by mapping one important customer segment route and identifying the decisions, handovers, and gaps. Then, agree on entry and exit rules, message priorities, and ownership.

(Source: Kate Barrett presentation for RARE 2026)

The goal is for each interaction to make sense in the context of what has already happened and what the customer needs next. Automation should support that experience.

S: How much personalisation is necessary for effective retention? When does it create complexity without improving value?

A first-time buyer may need guidance that an experienced customer doesn’t. Someone buying a gift may need different follow-up content from someone buying for themselves. A replenishment reminder should reflect the product and a realistic usage timeline.

These distinctions have a clear purpose, and they meet the customer or prospect where they are in their lifecycle.

For every additional signal from the data, I’d ask what decision it changes and how it benefits the customer. If we can’t explain this, we need to question the extra complexity.

There’s also the effort we create inside the communication itself. Adding more personalised product blocks, recommendations, and calls to action can leave someone with too much to process. 

Relevance on paper doesn’t automatically translate into an easy experience. 

We don’t want to overwhelm them, either in the email content we are asking them to understand, process, and act on, or in terms of where they are in their journey.

AI for smarter retention: What high-performing lifecycle teams will do differently

S: Which AI applications do you believe can materially improve retention, and where is AI being used mainly because teams feel they should be using it?

K: The applications I’m most interested in help teams understand customers better and act on that understanding.

This includes the following:

• analysing feedback and behavioural data; 
• identifying patterns worth investigating; 
• supporting predictive segmentation; 
• creating relevant content variations. 

Predicting replenishment needs, for example, gives us a useful hypothesis about timing that we can test.

AI can also help smaller teams access analysis and creative options that they would struggle to produce manually. This creates an opportunity to use their time differently.

The weaker use cases start with ‘We should be using AI’ and end with more content, more segments, or more journeys without a clear purpose.

I want to see whether it improves the decision, the customer experience, or the team’s capacity to do valuable work. Producing more material is only useful when that material serves a need.

S: What will distinguish high-performing retention and lifecycle teams over the next few years? If someone is rebuilding a mature CRM programme, what would you prioritise or stop doing?

K: I think the strongest teams will be better at connecting what they know about customers with the decisions they make every day. They’ll identify weakening relationships earlier, prioritise the changes that matter, and turn learning into a better way of working.

If I were rebuilding a programme, I’d start with the three practical moves I gave in my keynote:

1. Run one connected-journey audit. Pick a segment and examine everything they experience across channels over 30 days.
2. Establish one early-warning signal. This might be a widening purchase interval or a slowdown in an important journey interpreted in the context of that segment.
3. Retire one communication that survives purely because it has always been there (and isn’t producing meaningful results).

From there, I’d prioritise the biggest opportunities to strengthen trust, create value, reduce effort, increase relevance, and enable progress (building Customer Momentum™).

I’d also stop testing without a meaningful question and producing reports that never inform a decision. The team needs space to understand, improve, and learn alongside delivering the day-to-day programme.

Wrapping up

Thanks to Kate Barrett for sharing her expertise and practical insights with us. Through all her answers, we can see that effective email marketing goes beyond campaign performance. 

Email marketers should understand their customers, recognise when relationships begin to weaken, and make informed decisions that deliver value at every stage of the customer journey. By connecting lifecycle communications, testing with purpose, and focusing on what customers truly need, they can turn email into a powerful driver of long-term retention and business growth.