I don't think that's the point. The instructions are intended to give you an advantage in buying the correct bottles. I think the idea is that either the winning caps are difficult to read, since the code is random numbers and letters (or not all of it is visible), or that you'll look really weird taking a pad and pencil into the soda isle.

Regardless, if you read the instructions, I think it's implied that you'll be buying the winning sodas, in which case Bruno is right and you'd be a sucker for spending over a dollar to win a "free" song.

This promotion also assumes two things about me: I'm a Pepsi drinker and I would dare to darken iTunes's doorstep. Hells no on both accounts. What an insulting commercial that one is. Green Day disappointed me on that one.