Are there any guidelines or direction as to the appropriateness for folks to embed referral codes, affiliate sale codes, or similar things into links given in answers?
What prompted this question was that I noted in this question about photo sales sites, Pearsonartphoto responded with a list of services and each of the links includes a referral or affiliate code. Presumably he would receive some sort of credit or commission for folks who click through to the site and register.
I can see two viewpoints: one, being that as long as it's a quality answer it'll get voted appropriately and that there's no harm in rewarding the one who provided the answer. On the other hand, I could see folks rushing in to throw affiliate code answers when they might not be the best response.