Is Performance Max stealing credit for your brand searches?
The short version
Performance Max can serve ads to people already searching for your brand and count those sales as wins. Those people were mostly going to buy anyway. Check how much of its traffic is branded, use brand exclusions, and judge it on new customers and total revenue rather than its own ROAS.
Performance Max is Google's all-in-one campaign type. You give it budget, products, images and a goal, and it decides where to show your ads across Search, Shopping, YouTube, Display, Gmail and Maps.
For a lot of e-commerce brands it works well. But it has one habit worth watching: it's very good at finding people who were already going to buy from you.
What brand cannibalisation means
Someone sees your ad on Instagram, remembers your name, and searches for it on Google a few days later. If Performance Max shows them an ad and they click, it can count that sale as its own.
That person was already looking for you. Your normal organic listing, or a cheap branded search campaign, would very likely have got the sale. So Performance Max ends up looking brilliant, while doing less new work than its ROAS suggests.
The same thing happens with returning customers and people coming back from abandoned baskets. They're easy wins, and they flatter the numbers.
Signs it's happening
Performance Max ROAS is much higher than any other campaign, and it improved soon after launch with little else changing.
Your branded search campaign got quieter after Performance Max went live. Fewer impressions and clicks, as if something else picked them up.
Total revenue didn't rise in line with what Performance Max claims it's adding.
New customer numbers are flat while Google-attributed revenue climbs.
How to check
Google keeps changing what Performance Max reports, so the exact menus may look different in your account. Broadly:
Look at the search terms. Performance Max shows search term insights, and in many accounts now a search terms report. See how much of the traffic includes your brand name.
Compare before and after. Look at your branded search campaign's impressions and clicks for the months before and after Performance Max launched.
Line it up against your own revenue. If Google says it added a lot of revenue but your total sales and MER barely moved, much of it was probably already coming your way. More on MER here.
How to set it up properly
Use brand exclusions
Performance Max lets you exclude your brand terms, so it can't show ads on searches for your own name. Then run a separate, low-cost branded search campaign to cover those searches, where you can see exactly what's happening.
Point it at new customers
Performance Max has customer acquisition settings that let you bid more for new customers, or only for new customers. If growth is the goal, use them, and upload your customer lists so Google knows who's new.
Keep feeds and assets strong
Much of Performance Max's spend in e-commerce goes through Shopping. Clean product titles, accurate prices, good images and sensible product groups do more than almost any other setting.
Judge it on business numbers
Don't decide on Performance Max budgets from its own ROAS. Look at new customer acquisition cost, total revenue and MER over a few months. If you can, test it: turn it down in one region, or for a short period, and see how much total revenue actually moves.
Should you switch it off?
Usually not. Performance Max can find genuinely new customers, especially through Shopping and YouTube. The aim isn't to get rid of it. It's to stop it taking credit for the easy sales, so you can see what it's really adding and spend accordingly.
