Regarding the last "PC gaming in diyng!11!!" rants I'd like to remind you:
1) As you can see here, saying PC games are console-ports only is a plain bs:
http://adrianwerner.wordpress.com/games-of-2010/
2) DD is huge and if I'm not wrong platforms like Steam do not disclose the numeber of sales. And as Nefarious wrote most of the purchases come through online-shops.
3) Recently Battlefield Bad Company 2 (on its release) had more people playing the PC version of the game than the 360 or PS3 editions. (see news about it)