Editor’s note: Originally published 2024. Updated July 2026 with current context and refreshed guidance.
We have watched very large, “successful” companies collapse in recent years. WeWork, Allbirds, Thrasio, Zulily. Different businesses, same underlying story.
Part of the answer is that they were built in the era of growth at all costs. That era rewarded a strategic choice: focus on revenue, new customers, and traffic, and let the bottom line sort itself out later. It is easy to grow a business when there is always another round of funding coming. Most businesses cannot rely on that, and after several years of expensive capital, even the venture-backed ones have learned the lesson the hard way.
The bottom line is what matters most. Revenue and traffic are important, but revenue does not mean much if 20% of it went to advertising and your gross margin is 25%. There is nothing left to run the business. And if you sent thousands of people to your site and nobody bought, you have essentially flushed money down the drain.
Our goal here is to break down the metrics we feel are worth paying attention to most. Every business is different, and there may be a specific mix that is ideal for you, but these three are the ones that consistently separate healthy businesses from ones that only look healthy.
LTV: Lifetime Value
Customer lifetime value is the total revenue a customer generates for your business across their entire relationship with you, not just their first order. It is one of the most important numbers in your entire business.
Some business models produce naturally high LTV, like subscriptions, and some do not. Either way, you should always be looking for ways to increase the value of a customer. A footwear brand can increase LTV by telling past customers about a new shoe launch, increasing purchase frequency. An electronics company can offer accessories that lift average order value on every transaction.
Why does this matter so much? Because everything continues to get more expensive, especially advertising. Q4 CPMs now routinely run two to three times the annual average during peak weeks. If you continue to increase the value of a customer, you have two good options: let that value flow to the bottom line and strengthen the business, or reinvest it to acquire new customers at spends your competitors cannot sustain.
The brand with the highest LTV can afford to pay the most for a customer. That is the whole game.
In practice, the highest-leverage LTV tools are the retention channels: email and SMS automation. Top-performing brands now generate 38-45% of total revenue from those two channels, most of it from automated flows.
CVR: Conversion Rate
You got a potential customer to the site. They spent time learning about your product. They never bought.
Conversion rate is the percentage of visitors who take the action you want, usually a purchase. When ad costs are high, CVR is the multiplier on every marketing dollar, and monitoring it should always be a top priority. A low conversion rate usually points to one of two problems.
Better traffic needed. This is on your media buyer or agency. It is impossible to know with certainty whether you are sending the right person to the site, but a low conversion rate is often the first sign that the wrong people are arriving. One of the most common fixes is also the simplest: make the landing page match the ad that brought the visitor there.
A website that does not sell. Your website is your digital storefront and your sales team bundled into one. Ask yourself honestly: if you did not know your company, would you buy from your website?
Improving this is the discipline of CRO (conversion rate optimization), and it has matured well past button-color tests. Site speed matters enormously: every second of load time costs roughly 7% in conversions. Mobile experience, trust signals like reviews and clear shipping policies, and increasingly AI-driven personalization all move the number. The median landing page converts around 6.6%, while top performers clear 10%. That gap is worth real money.
You can run A/B testing tools yourself, or work with a team that specializes in CRO. Either way, treat it as an ongoing system, not a one-time project.
MER: Marketing Efficiency Ratio
Marketing efficiency ratio is less widely known than ROAS, but it has become one of the most important numbers in ecommerce measurement. The math is simple: total revenue divided by total marketing spend, across every channel.
When we first wrote this post, we said MER would grow more important in a cookieless, tracking-challenged future. That future arrived. Platform attribution is murkier than ever, and AI-driven campaign types like Performance Max and Advantage+ grade their own homework, routinely taking credit for sales that would have happened anyway.
MER cuts through all of it. It does not care which platform claimed the conversion. It answers the only question that ultimately matters: for every dollar we spent on marketing, how many dollars came back?
If you run very few channels, MER looks similar to channel ROAS. But if you are running many channels, and you should be, MER is the cleanest read on whether your marketing is working as a whole. Watch it as a trend line, not a single number: a falling MER while platform ROAS looks healthy is one of the most reliable warning signs in ecommerce.
For brands that want to go a level deeper, incrementality testing tells you which specific channels are actually driving that blended number. But MER is the place to start.
Frequently Asked Questions
What is a good MER for an ecommerce business?
It depends on your gross margin. A business with 70% margins can be very healthy at a MER of 3, while a 30% margin business may need 5 or better. Work backward from your unit economics: after product costs, marketing, and operations, what MER leaves a profit? That number is your floor.
What is the difference between MER and ROAS?
ROAS measures revenue attributed to a specific channel or campaign by that platform’s tracking. MER measures total business revenue against total marketing spend, with no attribution involved. ROAS helps you compare tactics; MER tells you whether the whole marketing program is actually paying for itself.
How do I increase customer lifetime value?
The proven levers: increase purchase frequency through email and SMS flows, raise average order value with cross-sells and bundles, and improve retention with a strong post-purchase experience. For consumable products, replenishment reminders timed to the usage cycle are some of the easiest LTV gains available.
The Metrics Are a System
LTV tells you what a customer is worth. CVR tells you how efficiently you turn attention into customers. MER tells you whether the whole machine is profitable. Track all three together and you can diagnose almost any growth problem. Track revenue and traffic alone and you can look successful right up until you are not.
Not sure which of these numbers is holding your business back? Book a strategy call with the Strat88 team and we will walk through your metrics together.
