I've most often seen this tactic in secondary products, with the goal of learning from (hopefully) representative visitors in a way that doesn't risk presenting

I've most often seen this tactic in secondary products, with the goal of learning from (hopefully) representative visitors in a way that doesn't risk presenting an unfocussed core offering. This sort of safety-zone data mining doesn't have to be limited to perfecting your pitch, either. I don't have any inside info, but Massive Health's The Eatery struck me as a very clever way to learn an awful lot about their potential users for whatever they're really working on behind the scenes.