A great film alone does not a blockbuster make. There's this pesky obligation to actually inform moviegoers about it, in order to get them into those cushioned movie seats. Unsurprisingly, this can often make or break a film's performance at the box office, especially during the summer movie season, when Hollywood rolls out its big guns and the key word is spectacle. Well, over the years, the industry has learned a thing or two about promotion and has created some truly innovative ads along the way. So here is a comprehensive look at some of the most groundbreaking ads for summer movies that have fascinated many and raked in big bucks to boot.