I had an Amazon site that was getting about 50-60 uniques a day and steadily increasing. Pretty much all of my 40 or so product pages were indexed. I added three AdSense units and my traffic immediately dropped to almost nothing, where it's been for the last few days. Now only 6 pages indexed, according to Webmaster Tools. Has anybody else seen this type of thing before? My only theory is that having a page filled with Amazon aff links AND AdSense units might flag it as a spammy site, but I really don't think that's it. Anyway, I've removed my ads and am waiting to see what happens. I'll let you know.