[chaosmachine]

I actually built another site around most of those ideas you just mentioned (but changed the idea to films, as I found they worked better):

http://filmvsfilm.com/

It's basically all user-generated-content, and it actually does rank on Google for a few things, but it's the wrong kind of traffic: People aren't in buying mode, very few visitors actually click through to Amazon and buy something.

[maushu]

Try changing the "Buy at Amazon" to "See it at Amazon", also show who is winning.

These are basically A/B tests.