No video assets is leaving PMax reach on the table

Performance Max serves across a wide mix of placements -- Search, Shopping, Display, YouTube, Discover, Gmail, Maps -- and each favors different asset types. A campaign built entirely from images has nothing to serve well on the video-first inventory it is still bidding into.

The signal worth checking

The signal worth checking is not just whether there are enough assets, but whether performance labels skew heavily toward the low end without a comparable share performing well -- creative fatigue at the asset-group level, the same underlying pattern as ad fatigue elsewhere, just less visible because PMax abstracts the placement away from the specialist reading the report.

A worked example

Illustrative case: an asset group carries twelve images and zero video assets, and has been running unchanged for five months. Performance labels on the images skew toward "low" for eight of the twelve, with only two rated "best" -- a shrinking pool of top performers carrying most of the campaign's weight, on a placement mix that includes YouTube inventory the account has never had a single asset capable of filling. The campaign's headline CPA still looks acceptable, because the two strong images are doing enough work to keep the average from breaking -- until they, too, fatigue.

The fix

The fix is not "add more of everything", it is closing the specific gap: video coverage for video-first inventory, and enough asset variety that the mix is not leaning on a shrinking pool of top performers to carry the whole campaign.

Why this is easy to miss for months

Nothing about a missing asset type shows up as a red flag in Google's own interface -- it is an absence, not an error, and absences do not trigger alerts. The campaign keeps serving, keeps spending, and keeps reporting a number that looks acceptable, right up until the small pool of strong performers it has been leaning on starts to fatigue too, with nothing new in the asset group to take over.