What is Performance Max, and when does it work for ecommerce?

What is a Performance Max campaign?

Google defines Performance Max as "a goal-based campaign type" that gives you access to all your Google Ads inventory from a single campaign. Instead of building separate Search, Shopping, Display and YouTube campaigns, you give Google the inputs and its AI combines them into ads for each channel and optimizes toward your goal.

What you control is the inputs:

• Conversion goals, plus an optional target ROAS or target CPA. Smart Bidding then bids on each auction's chance of converting.
• Asset groups: collections of headlines, images, videos and logos built around a theme or audience, which Google mixes and matches.
• Data feeds: for stores, the Merchant Center product feed.
• Audience signals: customer lists, remarketing lists and custom segments that tell Google who to look for first.
• Search themes to guide it toward high-value searches, and brand exclusions to keep it off queries you do not want.

How does Performance Max work for ecommerce?

For a store, the feed is the campaign. Google's developer documentation says the Google Ads account must be linked to an existing Merchant Center account, and you need at least one listing group, which decides which products the campaign can advertise. Adding an asset group switches on the Shopping and dynamic remarketing channels.

Google's retail best practices, in short:

• Give each asset group a distinct set of products, so you can see which product lines carry the campaign.
• Report transaction-specific conversion values, not a flat value per sale. Without real values, maximizing value is guesswork.
• Set target ROAS from what yields the most profit, accounting for cost of goods and customer lifetime value.
• Use the new customer acquisition goal if you want to pay more for first-time buyers than repeat ones.
• Keep the feed rich and current: full descriptions and images, and fresh prices and availability. Custom labels let you segment high-priority products.

Google reports that advertisers who moved from Standard Shopping to Performance Max saw 25% more conversion value on average at a similar ROAS, and suggests testing it with a one-click experiment. That is Google's own figure; run the experiment on your account before you believe it.

What goes in a Performance Max asset group?

Google's current specs. More assets means more formats Google can build; Google recommends at least 4 square and 4 horizontal images and video in every orientation.

If you add no video, Google may auto-generate videos from your asset group. Those auto-built videos are rarely how a brand wants to look on YouTube, so upload your own in all three orientations.

Performance Max vs Shopping, Search and AI Max: what is the difference?

Running Search next to Performance Max is normal. Google says that when a search matches an exact match keyword in a Search campaign, the Search campaign takes priority; Performance Max search themes have the same priority as phrase and broad match keywords.

AI Max is not a campaign type. It is a set of features inside Search campaigns: broader search term matching, customized headlines and descriptions, and final URL expansion. Google reports 14% more conversions or conversion value at a similar CPA or ROAS for advertisers who switch it on (internal 2025 data, non-retail advertisers).

When does Performance Max work, and when does it not?

Performance Max is only as good as what you feed it. It tends to work when:

• Conversion tracking reports real purchase values, so Smart Bidding optimizes toward revenue rather than any sale.
• The Merchant Center feed is clean: no disapprovals, prices that match the site, titles written for search.
• The budget is large enough to buy conversions every day, and nobody touches it for six weeks. Google warns that frequent changes to budget, bid strategy or status can reset learning.
• Creative covers every format, so Google is not stretching three images across YouTube and Gmail.

It struggles on a thin budget, a broken feed or a goal you cannot measure. It also absorbs branded searches you would win anyway, which flatters its ROAS: add brand exclusions and judge it on total profit, not the campaign's own report.

This is the work our Google Ads team does every week: feed, conversion values, asset groups and search terms, for $500 a month on Essentials or $1,600 a month with creative on Full Account Management.

How do you set up Performance Max for a store?

1. Fix the feed first. Clear every disapproval in Merchant Center and link it to Google Ads.
2. Check conversion tracking. Purchases should report the real order value, not a fixed number.
3. Choose the goal and bidding. Sales as the objective; maximize conversion value, with a target ROAS once you have data.
4. Build asset groups by product line. One group per category or margin tier, each with its own listing group and creative.
5. Add audience signals and search themes. Customer lists and remarketing lists first; themes for the searches you most want.
6. Add brand exclusions. Keep your own brand searches in a Search campaign you can measure separately.
7. Leave it for six weeks. Then judge it on total profit and new customers, not the campaign's ROAS alone.