Sure, however even if you have the affiliate info of 100 different booksellers, you're still favouring those 100. The fantastic thing about Wikipedia is that it

Sure, however even if you have the affiliate info of 100 different booksellers, you're still favouring those 100. The fantastic thing about Wikipedia is that it's so damn neutral and I think that introducing any kind of affiliate links (which I do agree is a good idea in theory) will likely damage that.