It seems difficult to make good money with affiliate marketing. Example Amazon books: say I earn 1$ per book sale - that is about the same as for 10 clicks on a

It seems difficult to make good money with affiliate marketing. Example Amazon books: say I earn 1$ per book sale - that is about the same as for 10 clicks on an adwords ad on my site. If 10 people have clicked on an Amazon link, I haven't earned anything yet. So how can such things make sense? I guess you have to sell more expensive stuff, but I think Amazon has also capped the max affiliate reward now? A pity, because I'd prefer to refer handpicked things to unpredictable AdWords on my site, but can't see it working.