Couple quick notes:
(1) The revelation that it only takes 3,000 sales of an entire product line to break the Top 5 of the RPG industry is a chilling number.
(2) Gareth, however, is being a little shifty with his numbers. Dresden Files was released at the end of June. While they've only sold 3,000 copies in Q3, note that the book only went on sale a couple of weeks before the beginning of Q3.
So what?
Well, the Top 5 list Gareth cites is based on retailer sales. Evil Hat's sales numbers for DFRPG are based on sales to distributors and directly to customers. Which means that the bulk of the 5,300 copies shipped to distributors at the end of Q2 were probably still being sold be retailers in Q3.
Admittedly, in similar fashion, books shipped to distributors at the end of Q3 would not be getting sold by retailers until Q4 or later. But Gareth also neglects to mention that the figures "omit a big hunk of September’s sales", which probably negates some of that.
In short, the numbers are probably larger than Gareth is suggesting.
But Gareth is also, IMO, pulling another fast one. He wants to condemn the entire industry to the dustbin, but he's limiting his figures to distributor sales. And while the DFRPG line has sold 8,300 copies to distributors, its actually sold a total of 15,000 copies through all sales channels.
The only message these figures really seem to convey, to my eyes at least, is that hobby stores are now making up a minority portion of the RPG industry.