Brave Search Uses Click Data in Search Ranking Algorithm

They may use return to SERP rate as a stronger signal. If a user views a page for under X seconds and then returns to search, one may assume that it wasn't relevant to their query. It acts similar to CTR as a ranking factor, but with an extra step.

wat? Google used clicks ("navboost") since approximately forever, it's one of strongest signals for all major web search engines. I guess the better question is why they don't optimize ranking directly on clicks, why still bother with all that expensive human raters business... well optimizing for clicks helps but only until a certain point beyond which it starts hurting relevancy by overpromoting old popular results and clickbait. But as an ingredient in overall ranking in one way or another they and everyone else definitely use click data.

> hard to monetize ads based on click data.

Google's main product, AdWords, directly monetizes click data by charging advertiser's per click. No click, no payment. Can't get much more direct than that.

My automated testing says they do use click data...

As little as 3 clicks seems to be able to bring an obscure page much further up the rankings for an obscure query.