You may have seen the Gillette ad campaign for "Man of Steel," which asks "How Does Superman Shave?" — a question that has probably inadvertently sold quite a few razor blades whether there's really a legit answer to it or not (ours is "Like everybody else," but hey).

Ad campaigns and product placement are unavoidable parts of the big business of Hollywood, especially when it comes to summer blockbusters that will lure several million potential consumers. Several companies vie for some sort of lucrative cross-promotional deal with a film, hoping that the sight of a movie star (and/or superhero) will up the profits of their wares. Sometimes it works ... and sometimes it never happens.

Here are six ad campaigns for "Man of Steel" that never made it past the make-believe stage. Check 'em out, and then go book that flight on Delta anyway.