Cross-promotional contests are weird. Someone always seems to be trying to shoehorn one big-deal brand into another, in the apparent hopes that one brand’s popularity will rub off on the other.

And as much as I love both Rock Band and Pepsi — and oh, I do  — I have to say the Pepsi Rock Band Music Video Contest that’s been running over the summer is no exception. The concept is this: Shoot a video of your Rock Band band playing songs from the Rock Band catalog. And, include Pepsi products? I dunno, something like that. The winner is chosen by the voting public, and receives — get this — a “Moonman,” the traditional award of the MTV Video Music Awards. At the VMAs. In the category Best Performance in a Pepsi Rock Band Video. Oh, also: Yahoo! is involved somehow.

My brain hurts.

Anyway, I just wanted to let you know that if this sort of thing floats your boat, you only have until September 1st to head to www.pepsirockband.com and vote for your favorite video of people who may or may not have ever played an instrument before, plastic or otherwise.