Sigh. We have gone over this before...and I did not want to re-hash it, but I can't stop myself, so guess I will.
Amazon is best as a relative ranking. No D&D products have come close to these numbers in 12+ years (there are links up thread), so they are almost certainly the best selling in 12+ years, especially as our other data like ICV2 is consistent with that.
Still, it is tempting to speculate as to absolute sales. Its important to understand that their are millions of books available through amazon. You can have a sales rank of 3,000,000 or lower. Authors in their discussions will often focus on ranks anywhere from 500 to 50,000. The PHB and all the core products are doing better then that.
Various places on the web try to estimate sales from rank. Here is one:
http://www.fonerbooks.com/surfing.htm
Based on this and other things I have seen, its probably closer to 100 or a little lest per day for the PHB. Which is nice. Say around 30,000 per year. When the PHB was closer to #1, then of course sales would have been much higher.
In any case, it would still take a long time to get to a million (the old guestimate for the 1E and 3.0 PHBs). But of course Amazon is just one sales channel. But if it is doing well there, it is probably also doing well through the other channels. Again, the relative number is what counts.
