Performance Max has fundamentally changed how Shopping campaigns work, and a lot of D2C brands are still treating it like a black box they have no control over. In reality, PMax performance is driven almost entirely by the quality of the inputs you give it: your product feed, your asset groups, and your audience signals.
The biggest lever most brands ignore is feed quality. Titles, images, and structured data directly affect which queries your products get matched to. A messy feed means PMax is essentially guessing, and guessing is expensive.
The second lever is asset groups. Feeding PMax strong creative assets gives it more to work with across Display, YouTube, and Gmail placements, which often unlocks incremental reach beyond Shopping alone.
Finally, audience signals matter more than most advertisers realize. Uploading customer lists and first-party signals helps PMax find lookalike buyers faster, especially in the first few weeks of a campaign when it is still learning.