was a discussion a few days ago.
I dont think Google has a problem if you include the affiliate bit in the creative, as for Amazon, who knows?
Shak
Generally for Books, CDs and lot of over Amazon items it isn't worth the bother considering the conversion rates involved, unless you run a very tight operation and can generate substantial volumes of clickthrough traffic. Effectively a 'low margin high volume operation'.
I run mostly high-priced items (Box Sets for DVDs, some ~$300 electronics items), so it ends up working out.
Unfortunately, my biggest seller hiccuped the past couple of days, so now I'm out quite a bit.
I'm chalking it up as a learning experience -- It's taught me the value of diversity. :)
EDIT:
It's nice to know that its kosher with Google. I do list Affiliate (or a shortened form thereof) in all my ads, so I don't feel I'm being at all deceptive about it.
Hopefully Amazon doesn't have a problem with it, because I just sent $1,500 worth of shipped sales their way over the past 4 days.
not sure how amazon feels about the direct link, although, as noted, google allows it provided the destination URL shown in the ad is the actual destination.
(I've got an email from them about this very thing, which I can't post, but if anyone wants the details, they can sticky me)