Some people do well with it. Though I have never done much with it myself. If I remember right it has a one day cookie, so you better have a good presell page before you send them to amazon.
It's not easy to make good money with amazon. They have very low start commission of 4%. But there are other kind of commissions also. Try to sell thinks that cost more, so your commission will be higher.
I've been using Amazon for awhile. It honestly is a low commission program and unless you have a lot of draw it's not one that is overly useful. However they do have one huge thing going for them that if aren't useful for your main sites can be used in smaller sites (which is what I do.) The one huge thing? One of the largest commission based inventories that you can run across. Again this isn't something I would attempt to make a living on (though I hear it happens) but if you have a large enough network of sites and want to partially include Amazon into some of them it can help. My opinion anyway
yah...I cant figure out how people can run it as a primary source. If a site has 10000+ a day then i might partially include it, just for the heck of it.