This is not without precedent in the ad industry, although the level of subtlety varies a lot. Billboards are a notable example, because the medium is in-house

This is not without precedent in the ad industry, although the level of subtlety varies a lot. Billboards are a notable example, because the medium is in-house and there's almost always latent inventory. Adams Outdoor once advertised the fictitious, toilet humor brand 'Outhouse Springs', then years later the seemingly personality-enhancing wonder drug 'Reachemol'. Lamar's Milwaukee division advertised a cat doctor with a preference for chocolate who healed 'boo-boos with nom-noms'. This is essentially a big A/B test, and unlike billboards, they can collect fine-grained data on how people interact with the ad.