Google favors high-rated RSAs, but lower-rated ads convert more

Google is giving more of your budget to whichever responsive search ad in an ad group carries the higher ad strength rating. That ad converted better less than half the time, so the label can quietly pull traffic away from your best performer.

Responsive search ads (RSAs) are ads where you supply several headlines and descriptions and Google mixes them. Each ad gets an ad strength rating, from Poor to Excellent, that measures how varied and complete those assets are.

What changed

Brad Geddes, co-founder of Adalysis, studied more than 5,900 Google Ads accounts and reported the results in a Search Engine Journal article. In ad groups with two active RSAs carrying different ratings, the higher-rated ad got more impressions 63% of the time. That is up from 56.8% in Adalysis's 2022 study.

Performance went the other way. The higher-rated ad had the higher conversion rate only 45% of the time. Across all ad groups, higher-rated ads ran an 11.8% higher cost per acquisition (CPA). In Brad's example, a $100 CPA lower-rated ad faced a higher-rated rival at $111.80.

Google's Help Center says ad strength "doesn't directly influence your ad's serving eligibility," and the article quotes Ginny Marvin, Google's Ads Product Liaison, saying it "isn't used directly in the auction." The article doesn't include a Google response to the new study, and Google hasn't said whether it plans to change how it serves these ads.

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The main reason the lower-rated ads win is pinning. Pinning locks a headline or description to a specific position. Pinned ads often rate lower, and they often convert better, because they're written to filter out the wrong clicks. When ads weren't pinned, a higher rating did line up with higher click-through rate and better cost per conversion at each step.

What it means for you

This matters most if you run two or more RSAs in the same ad group, and especially if you've pinned headlines to protect a price, a disclaimer, or a service area. If you have one RSA per ad group and no pins, the rating mostly tells you whether your headlines are varied enough, and that's still worth fixing.

Doing nothing has a real cost. If a pinned ad is your best converter but carries a low rating, Google may keep showing its rival, and your CPA can climb with no change to your offer.

What to do

1. Open your Google Ads account and go to Campaigns > Ads & assets > Ads. Review the ad strength of every responsive search ad.
2. Open each ad in the editor and note whether it's unpinned, partly pinned, or fully pinned. Judge each group against its own peers, since a pinned ad's rating means something different.
3. For unpinned ads, aim for Excellent with at least 11 distinct headlines that mix keywords, benefits, features, calls to action, and proof points. Rewrite near-duplicates before you add more.
4. For pinned ads, Brad's process is to remove the pins, build the ad to Excellent, then re-pin and add assets until the rating reaches at least Average (or Good if you pin one headline). If you must pin a position, use three or more different headlines there, because pinning only one or two caps the ad at Good.
5. Judge tests on cost per conversion, not the rating. Give mismatched tests more time, since the lower-rated ad will collect fewer impressions. If a pinned ad wins on CPA, keep it running.