I was very skeptical when I first joined the Amazon affiliate program. The commissions seemed very low comparable to others programs that give 50% or even more. But there are some reasons which make the program very good:
1) Amazon gives XML feeds for a lot of products, more than anyone else in the market. They also have reviews and descriptions in the feeds so you can create user and search engine friendly pages using them.
2) In your Amazon pages you can run Kontera and Adsense increasing your revenue lot. Adsense+Amazon+Kontera is one of the best user friendly combo you can use.
3) Amazon is a serious company and they will always pay.
And what is bad about amazon:
1) They don't offer alternative payment methods such as paypal, egold or moneybookers
2) They pay quarterly
3) They should give higher commissions and better stats reports.