A recent survey at Rock Paper Shotgun has shown that 47% of all PC games purchased are digital downloads.
According to the survey, 93% of PC gamers have bought a game via digital download over the last year, as opposed to the 7% who buy purely retail boxes. Additionally, 71% have bought over 4 games digitally during the last year period.
These figures aren't surprising, as it is much more viable nowadays for digital downloads, with the always-increasing internet speeds, and the general rule that digital downloads are cheaper than buying retail.
News source: Rock Paper Shotgun