I've been running affiliate links on the book reviews on my blog. Stats here: <a href="https://gist.github.com/swanson/4711006" rel="nofollow">https://gist.github.com/swanson/4711006</a><p>It makes about $20/yr.
At least as good as Adsense for me, but payments outside of US are horrifically slow. It can take even up to 4 months to receive the checks. It's like Amazon has never updated their affiliate program since they started it a decade ago.