But what's the supposed ground truth that spouses and algorithms were tested against? Self reporting? Some other glorified coin flip algorithm that maybe just did the same mistakes as the "thumbs" algorithms? An export panel populated with people that, unlike the benchmarked spouses and acquaintances, used the same jargon as the algorithm authors?

(Glancing over the footnotes it seems to be (b), some other algorithm)

The beauty of adtech: it's perfectly fine to be wrong as long as advertisers think you are right.

On meta level, this "better than your lover" meme/study is surprisingly enlightening.