Getting sales data for the PC market is hard. The NPD Group try, but they don't cover digital downloads, so there are big holes in their data. Enter Rock Paper Shotgun's ginormous reader survey.
In an effort to try and get a sense of how many PC purchases are of the digital variety, the PC-focused site set up a poll. Sure, they're "just" a blog, and no, they don't do this kind of thing for money, but as the survey's disclaimer notes, almost two thousand people responded. Considering that's almost two thousand hardcore PC gamers, we'd call that a suitable sample audience and then some.
The results found that 93% of PC gamers bought at least one game digitally in the last 12 months. 71% of respondents bought more than four games digitally. That leaves the number buying games solely from a retail store at a meagre 7%.
Most alarming of all, however, is that after a little mathematics, the RPS team worked out that 47% of all PC game purchases in 2008 (at least among this survey group) were digital ones.
You ever wonder why people like Valve and Direct2Drive never release sales data for their services? It's not because they're covering for how few sales they make. They're making sure they can keep that sweet, sweet honey pot all to themselves.
PC Game Sales: 47% Of PC Purchases Are Digital [Rock Paper Shotgun]