>I literally cannot think of a company that "won" by promoting its ethical competitiveness,

Just off the top of my head there's starbucks whose main marketing innovation when they opened up was that they use only "fair trade" beans. And there's American Apparel, which despite the recent controversy, started off with the marketing promise that they are sweatshop free.

I don't know how much ethics matters, but certainly it matters to some extent.