Performance Max divides opinion among people who run Google Ads. Some accounts do brilliantly on it. Others pour money into it for months without anyone being able to say what the money bought. In our experience the campaign type is rarely the problem on its own. It works well when you give it good data and clear limits, and it wastes money when you hand it a budget and hope.
We run Search, Shopping and Performance Max for Masterclip, a UK ecommerce brand selling horse clippers and grooming products, and have done for more than three years. This guide explains what Performance Max actually does, when we'd use it, and the checks that stop it drifting.
What Performance Max is
Google describes Performance Max as a goal-based campaign type that gives you access to all Google Ads inventory, including YouTube, Display, Search, Discover, Gmail and Maps, from a single campaign. You supply the ingredients: a conversion goal, a budget, your product feed if you're a retailer, and a set of assets such as headlines, images and videos. Google's systems then decide where to show your ads, to whom and with which combination of assets.
Google pitches it as a complement to keyword-based Search campaigns rather than a replacement for everything, and we'd take that seriously. The danger with any automated campaign is that it finds the easiest conversions available, which aren't always the ones you'd have paid for.
Where it tends to work
For ecommerce, Performance Max is usually at its best when three things are true. The store has a clean product feed with accurate titles, prices and stock. Conversion tracking records real purchases with their values. And there's enough volume for the system to learn from, because an account with a handful of sales a month gives it very little to work with.
When those are in place, it can find buyers on placements a Search-only account would never reach, and the ability to show products across YouTube and Discover can be useful for brands with a visual product. Our guide to Google Ads costs explains how budget and conversion volume interact more generally.
Where it burns budget
The most common problem we see is brand traffic. If someone searches for your business name, they were probably going to buy from you anyway. Performance Max can pick up a lot of those searches and report the sales as its own, which makes it look far better than it is. Google now offers brand exclusions in Performance Max for exactly this reason, and we'd apply them in most accounts that already run a separate brand Search campaign.
The second problem is poor tracking. If the campaign is optimising towards something that isn't a real sale, such as a page view or an "add to basket", it will happily deliver more of that thing. Check what's counted as a conversion before you look at any results.
The third is a feed that treats every product the same. If your bestsellers, your slow movers and your low-margin items all sit in one group with one target, the budget will flow to whatever converts most easily, which might not be what makes you money.
Organise products by how they perform
This is where a lot of our time on Masterclip goes. Rather than lumping the whole catalogue together, we group products by how they're actually performing and review those groups regularly. Products that sell strongly can be given room to scale, while products that get clicks without sales can be separated out and given a different budget or target.
Product titles are part of the same job, and we keep improving Masterclip's Shopping titles rather than treating them as a one-off, because the title is one of the main things Google uses to match a product to a search. If your feed titles are just product names, you're leaving a lot of matching to chance.
Keep the controls you have
Performance Max offers less control than a Search campaign, but it isn't a black box. You can set brand exclusions, add negative keywords to block searches you don't want, exclude placements and apply content suitability settings. Use them. A campaign with no exclusions at all is a campaign nobody is managing.
Look at the reports that are available too. Insights and search term data show what's driving results, and asset reporting tells you which images and headlines are pulling their weight. An account like Masterclip's gets checked often, because something nearly always needs adjusting.
Should you use Search and Shopping alongside it?
For most of the ecommerce accounts we'd consider, yes. Keeping a brand Search campaign separate gives you a clean read on how many sales come from people who already know you. Keyword-based Search campaigns for your most important non-brand terms let you control the message and the landing page for the searches that matter most. Masterclip runs Search and Shopping alongside Performance Max, and hobby owners and professional grooms each get their own messages and landing pages, which would be hard to do through Performance Max alone.
Whether a standard Shopping campaign is worth keeping alongside Performance Max depends on the account. Some stores find it useful for products they want to control tightly. Others find the two compete. Test it on your own data rather than following a rule.
How to tell if it's working
Judge Performance Max on sales and revenue in your own store's figures rather than on what Google Ads reports alone. Compare total online sales before and after, look at how much of the reported revenue came from brand searches, and watch the return on ad spend for each product group. If the campaign's reported results keep improving but your overall sales don't move, it's probably taking credit for sales you'd have had anyway.
Masterclip's case study is a useful example of judging on the right number. Its monthly reports lead with sales, taken from the store's own sales platform and analytics, and the business has grown by double digits every year for three years running. That growth comes from the website, SEO, Meta ads and Google Ads working together, and we'd be wary of anyone who credited it all to one campaign type.
Frequently asked questions
Is Performance Max good for small businesses?
It can be, but only with reliable conversion tracking and enough sales for it to learn from. Very small accounts often do better starting with Search.
Can I add negative keywords to Performance Max?
Yes. Google lists negative keywords and brand exclusions among the controls available in Performance Max.
Should Performance Max replace my Shopping campaigns?
Not automatically. Test it against your current setup and judge the results on your store's own sales data. If you'd like a second opinion on your account, our Google Ads team can take a look, or you can get in touch.