Movie Poster Oddities

I spent a few minutes on one of my favorite movie sites, and I've noticed a few weird trends in poster design:

The Black & White Alternating Backgrounds, Title in Color, Brooding Intensity...
The Hint, Hint, Guys! It's a Date Movie, And You Best Buy Her Some Roses Beforehand...The Hero in Deep Thought Stance...
Finally, the Silhouetted Guy on the Horizon with Muted/Duo-toned Background, a.k.a the "Private Ryan"