Ethics of using referral codes on SDMB

This might end up as a Great Debate, but it seems minor enough that I’m posting it here. Now that iTunes, Amazon, and (I’m sure) many other retailers have affiliate referral deals, is it ethical to post a recommendation for a book, movie, or album that includes your own referral?

Assume for the sake of this discussion that you were going to post the link regardless of the referral. Obviously spamming with referrals is right out.

I know we’re not supposed to advertise on the boards, but I see Amazon links all the time, so they’re obviously not frowned upon in general. Does the fact that a doper might make a little extra cash as a result make them distasteful? What if the Boards themselves replaced all such links with their own referral codes?

My opinion is that people using referral codes or the Boards intercepting them wouldn’t bother me at all, but that allowing individual codes might make it a bit harder to distinguish legitimate recommendations from people fishing for money.

I lurk on some other boards where there’s a strict no referral-link policy.

I think it’s a good policy for that board and that it would be good for here as well as we’ve developed ourselves into a community (largely) built on trust. If someone starts shilling for this or that and gets a kickback from Amazon or wherever else, then that trust starts to erode. If someone’s recommending that I buy some particular widgets, I want to know that they’re being recommended because that person has used those widgets and found them to be good. I don’t want to get a recommendation simply because they’re getting money out of it.

Happily, if someone’s paying attention, referral links are pretty easy to spot since they generally tag “referrer=236WE3456” or something similar at the end.