Don't put it on mainspace external links*, but put it on the Special:Booksources URL, and see what happens. --
- Andrew Gray
If it's decided to do this, maybe keep the original links at http://en.wikipedia.org/w/index.php?title=Special:Booksources&isbn=9780521405683#Individual_online_booksellers and add the affiliate links clearly marked as such after them.
Many sellers will then ask to be included in that list - what will the minimum requirements be?