Cheap evidence: Hacker News is full of people trying to get rich by selling something (usually access to web applications), and e.g. "Predictably irrational" has been mentioned. The marketing guru Seth Godin says he's been influenced quite a bit by Poundstone's "Priceless", which "dives into the latest psychological findings".

Of course, this is only informal evidence, only shows "some marketers" and only shows "believed to be useful".

Waveman's comment also seems relevant.