In order to get me clapping like a barking seal, all a movie trailer really needs to contain is Paul Giamatti, Alec Baldwin in a stupid wig, a "wilting boner" sound effect, a monkey dressed as a leather daddy, or any song from the '80s that I remember fondly from my youth. Oddly, the Rock of Ages trailer contains all of those things—and Tom Cruise! I love Tom Cruise! that dude's crazy!—but what I am doing right now is not clapping. Weird.
The "wilting boner" sound effect is at 0:31, FYI.