Growth is flat, margins are tightening, the board wants answers.

By Phill Manson, Founder & Managing Director, VALIX

I've been having the same conversation for about five years now. Different brand, different category, different agency behind them. Always the same conversation.

It goes like this: growth is flat, margins are tightening, the board wants answers. We pull the data. Repeat purchase rate is somewhere between embarrassing and alarming. According to Smile.io, only 27% of customers return after a first purchase, and once they've bought a second time, there's still less than a 50/50 chance they'll buy a third. The acquisition cost has been rising steadily for eighteen months. And when I ask how much budget goes into retention versus acquisition, the answer is almost always some version of 'we handle the email in-house.'

That last part is where it unravels. Email in-house, managed by someone who's also doing four other things, running broadly the same flows they set up two years ago, reporting on open rates that Apple inflated in 2021 and nobody updated the benchmarks for. The acquisition team, by contrast, has budget, headcount, and a weekly performance review.

This is not a failure of intent. It's a failure of incentives, and of the way the industry has trained marketers to think about growth.

The Metric We Were Sold

ROAS became the lingua franca of ecommerce performance because it's simple, fast, and feels like accountability. You spend a pound, you get four back. Job done.

Except it's not. ROAS tells you the ratio of attributed revenue to ad spend. It says nothing about whether that revenue was profitable after fulfilment, returns, and customer service costs. It says nothing about whether those customers will ever buy again. And it says nothing (absolutely nothing) about whether the value of those customers justified what you paid to acquire them.

A 4x ROAS with a 10% repeat purchase rate isn't a success story. It's an expensive revolving door.

The metric that actually matters is Customer Lifetime Value relative to Customer Acquisition Cost. A CLV:CAC ratio of 3:1 is the widely cited healthy benchmark; anything below it suggests you are spending unsustainably to acquire revenue. In my experience, a surprising number of brands either don't know their ratio, or (when we calculate it together) discover it's hovering just above 1. At that point you're not building a business. You're running a very costly break-even exercise.

Why Retention Gets Treated as the Quiet Cousin

Part of the problem is structural. Acquisition is fast. You spend money on Monday, you see traffic on Tuesday, you see sales on Wednesday. The feedback loop is short and satisfying. Retention is slower, messier, and harder to attribute. It requires patience, data maturity, and a willingness to invest in relationships rather than transactions.

There's also, frankly, an agency incentive problem that nobody in the industry talks about loudly enough. The marketing services ecosystem is built around acquisition. Media buying, paid social, performance marketing: these attract the biggest budgets and the most talent. Lifecycle, CRM, retention: these tend to get a fraction of the investment, often handed to a junior team member who also manages the Instagram account.

I've spent fifteen years in this space, first at RedEye and then building PAASE into one of Europe's leading Klaviyo agencies. Retention isn't the consolation prize for brands that can't afford to scale ads. It's the thing that decides whether scaling ads was worthwhile.

What a Retained Customer Actually Does for Your Business

Let me be specific, because 'retention is important' is the kind of statement that sounds obvious and gets ignored.

A genuine repeat customer, one who's bought three or more times, engaged across channels, and has a relationship with your brand, does several things that a first-time buyer doesn't:

They spend more per order. Bain & Company data shows loyal customers spend 67% more in months 31 to 36 of their relationship with a brand than in months 0 to 6. That is not theoretical. It shows up consistently in cohort data.

They cost almost nothing to market to. You have their data, their purchase history, their preferences. You're not bidding against competitors for their attention on Meta.

They are far more receptive to new product launches, upsells, and limited editions. Research by Invesp puts the probability of selling to an existing customer at 60 to 70%, versus just 5 to 20% for a new prospect.

• They spend more per order. Bain & Company data shows loyal customers spend 67% more in months 31 to 36 of their relationship with a brand than in months 0 to 6. That is not theoretical. It shows up consistently in cohort data.

• They cost almost nothing to market to. You have their data, their purchase history, their preferences. You're not bidding against competitors for their attention on Meta.

• They are far more receptive to new product launches, upsells, and limited editions. Research by Invesp puts the probability of selling to an existing customer at 60 to 70%, versus just 5 to 20% for a new prospect.

• They refer people. Word of mouth remains the highest-converting acquisition channel available, and retained customers are the ones generating it.

• They're resistant to competitor discounting. Someone with a genuine relationship to your brand doesn't leave because a rival is running 20% off. A one-time buyer absolutely does.

• They refer people. Word of mouth remains the highest-converting acquisition channel available, and retained customers are the ones generating it.

• They're resistant to competitor discounting. Someone with a genuine relationship to your brand doesn't leave because a rival is running 20% off. A one-time buyer absolutely does.

Frederick Reichheld of Bain & Company, published in Harvard Business Review, showed that a 5% improvement in customer retention can increase profitability by anywhere from 25% to 95%, depending on the sector. That's not a rounding error. That's a different business.

The Practical Question

I'm not arguing against acquisition. You need new customers. But acquisition without a retention infrastructure is burning money. And doing it in a way that looks fine on a dashboard right up until it isn't.

The question isn't whether to acquire. It's whether you're acquiring customers worth keeping, and whether you have the systems to keep them.

That starts with knowing which of your existing customers are actually valuable. Not by gut feel, but by data. RFM analysis (Recency, Frequency, Monetary value) is the foundation. Understand who your best customers are, where they came from, what their first purchase looked like, and how quickly they came back. That tells you what you should be optimising your acquisition spend to find: not just who converts, but who returns.

The best acquisition strategy starts with understanding why your best customers stayed.

From there, it's about building the lifecycle infrastructure to act on what you know. Not a welcome series and an abandoned cart flow and calling it 'automation.' A genuinely intelligent programme that responds to behaviour, identifies risk before a customer goes lapsed, and communicates in a way that earns the next purchase rather than just asking for it.

A unified customer view matters enormously here. If your purchase data is in Shopify, your email engagement is in Klaviyo, your on-site behaviour is in GA4, and nobody's connected them, you're flying blind. You have the data. You're just not using it.

The Honest Version of This Conversation

The brands growing profitably right now are not necessarily the ones with the biggest ad budgets. Several of the most commercially impressive D2C businesses I've worked with in the past two years have actually pulled back on acquisition spend while improving total revenue. Because they got serious about the value of the customers they already had.

They stopped measuring success through their ESP's attributed revenue number (which, if you're still reporting that to your board, we should have a separate conversation about how misleading that figure is). They started tracking repeat purchase rate, CLV by cohort, and revenue from existing customers as a proportion of total. Those metrics tell a different and more honest story.

If you want a starting point: calculate your CLV:CAC ratio by acquisition channel — the 3:1 benchmark is a reasonable floor — and look at your 90-day repeat purchase rate against the Smile.io benchmark of 27% first-purchase return rate. If either number makes you uncomfortable, good. That discomfort is useful. It's pointing at something worth fixing before it becomes the reason growth stalls.

Sources

Reichheld, F. (Bain & Company), 'The Value of Keeping the Right Customers', Harvard Business Review, 2014. A 5% increase in retention rates can increase profits by 25-95%.

Gallo, A., 'The Value of Keeping the Right Customers', Harvard Business Review, 2014. Acquiring a new customer is 5 to 25 times more expensive than retaining an existing one.

Smile.io Loyalty Data. After a first purchase, customers have a 27% probability of returning. After a second purchase, the probability of a third rises to 45%+.

Bain & Company. Loyal customers spend 67% more in months 31-36 of a brand relationship than in months 0-6.

Invesp. The probability of selling to an existing customer is 60-70% vs. 5-20% for a new prospect.

CLV:CAC 3:1 benchmark: widely cited acroQss Paddle, McKinsey, and HBR as the baseline for healthy ecommerce unit economics.

Phill Manson is Founder and Managing Director of VALIX, an AI-driven customer growth consultancy and Klaviyo Platinum Partner. He has spent fifteen years helping ecommerce and D2C brands turn customer data into profitable, repeatable growth

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