Moving Beyond ROAS: The Rise of MER

ROAS is a platform metric. It tells you what Meta thinks it did. In a world of privacy changes, iOS attribution gaps, and "dark social," ROAS is increasingly becoming an unreliable compass — and brands that make decisions based solely on platform-reported ROAS are flying partially blind.

At User Actually, we look at MER: Marketing Efficiency Ratio. It's a simpler number, and a more honest one.

What MER Actually Measures

MER represents your blended marketing efficiency. It doesn't care whether the sale came from a Meta ad, an email flow, a Google search, or a word-of-mouth referral that turned into a direct visit. It tells you one thing: for every pound you spend on marketing, how many pounds come back in revenue?

Why MER Matters for Scaling Brands

Here's where MER becomes genuinely powerful: if your Meta ROAS is declining, but your MER is holding steady, it usually means something else is working. Your ads are generating awareness, that awareness is creating Google searches, and those searches are converting. The platform doesn't get credit for the full journey — but your MER does.

When you stop obsessing over platform ROAS, you stop making panic decisions based on incomplete data.

This matters enormously for channel investment decisions. Brands that only look at platform ROAS will turn off channels that are contributing to revenue indirectly. Brands that look at MER can see the whole picture — and make decisions accordingly.

How to Use MER to Guide Scaling

Find your healthy MER range

For most ecommerce brands, a total marketing spend of 15–25% of total revenue is the sustainable range. That translates to an MER of between 4 and 6.5. Where you land within that range depends on your margins, your growth stage, and how much of your revenue is coming from retention vs. acquisition.

Track it weekly, not monthly

MER can shift fast when you change spend levels or launch new campaigns. Weekly tracking lets you see the signal before it becomes a problem — and confirm that scaling decisions are working before doubling down.

Use it alongside, not instead of, channel data

MER doesn't replace channel-level reporting — it contextualises it. If MER is strong but one channel's attributed ROAS is weak, that's a signal to investigate, not to cut. The channel may be contributing to the system in ways that attribution doesn't capture.

The Bigger Point

Growth isn't about one platform. It's about the blended system. The brands that scale most profitably are the ones who measure the whole — and make decisions based on what the whole is telling them, not what one dashboard says.

When you start measuring MER, you start managing your marketing like a business rather than like a campaign. That shift in perspective changes which decisions you make, and how confident you are when you make them.