Beyond Conversion Rate: rethinking CRO metrics

Let me start with a confession: I’ve spent my entire career optimising for conversion rate (CR%). I’ve tested headlines, layouts and CTAs in pursuit of that sweet, incremental bump in CR.

Conversion Rate Optimisation (CRO) is still one of the most effective levers for increasing sales on a website. But lately, I’ve been rethinking things. What if CR% is… a bit of a trap?

Not useless – just suboptimal. Especially if you care about what most businesses actually care about: revenue and profit.

Full disclosure: this article is a near-total ripoff of a great piece on Conversion Volume Optimisation by Optimize Smart. I’m mostly writing this to learn and think out loud — but if you’re also stuck in the CR% mindset, you might find it useful too.

Why CR% is an imperfect metric

Conversion rate is a ratio metric — conversions divided by traffic. That sounds sensible until you look deeper:

• A higher CR% doesn't always mean higher revenue.

• A lower CR% doesn't necessarily mean a test failed.

• It has no correlation with cost and only a weak correlation with revenue.

• And because it’s a ratio, it can be easily distorted. Get more top-of-funnel traffic and CR% drops — even if you're making more money.

Let’s make this real:

Example: Revenue up 50%, CR down 40%

In one test, we reduce friction at checkout for high-AOV customers. Conversion rate tanks — but revenue shot up. Why? Because the few who convert, spend big.

Example: CR up 16%, but revenue down 30%

In another test, CR goes up but transactions drop. We attract the wrong kind of traffic – they convert more often, but spend less, and don’t return.

Example: CAC up 250%, CR up too — but gross profit down 19%

A campaign drives conversions, but at a cost. The margin gets swallowed by acquisition costs.

So what should we optimise for?

There are really only two metrics that reliably drive revenue:

✅ Average Order Value (AOV)
✅ Purchase Frequency

CR only sometimes helps with those.

If you want to grow a business, you're better off optimising for conversion volume — how many actual orders you get, not the rate at which you get them.

Conversion volume optimisation (CVO)

A lesser-known but important concept, Conversion Volume Optimisation (CVO) shifts focus from ratios to real numbers.

Where CR% tells you the proportion of people who bought, conversion volume tells you how many did. It’s unambiguous, easy to report, and instantly understandable.

“300 conversions” is just that — 300 conversions.
Month 1: 300 orders. Month 2: 410 orders. No interpretation required.

Compare that to:

“Your CR went from 1.72% to 2.15%” — cue the blank stares from clients.

When to focus on CVO instead of CR%

CVO is especially useful when:

• You're doing high-volume eCommerce.

• You have paid traffic strategies where costs matter more than percentages.

• You want to report business outcomes, not performance metrics.

• You're experimenting with pricing, bundling, or upsells (which affect AOV more than CR%).

It’s worth noting: CR% still has its place. It’s a strong indicator of traffic quality and usability. If you’re diagnosing friction on the site or comparing different channels, it’s useful.

But if you want to grow a business – not just improve a website – you need to zoom out.

This isn’t just semantics, it’s strategy

Optimising for CR suggests the goal is to get more people to click “Buy.” But that’s a narrow definition of success. Real growth happens when you think like a marketer, not just a UX nerd.

As Jay Abraham famously said, there are only 3 ways to grow a business:

1. Increase the number of customers

2. Increase the AOV

3. Increase the frequency of purchases

CR directly impacts #1, sometimes impacts #2, but almost never #3. Yet most CRO strategies focus only on #1.

So what now?

This article is partly a note-to-self. I’ve spent years treating CR% as the North Star. But it’s just one dial on the dashboard.

Going forward, I want to explore optimisation strategies that align better with business goals: higher lifetime value, better margins, and sustained growth. And that means looking beyond the % sign.

Let’s call it what it is: Revenue Optimisation.

If CRO is about user behaviour, this is about business behaviour. And maybe it’s time we merged the two.