According to research firm NPD Group, digital sales for PC gaming have risen quite a bit and are now closing in on retail sales. We can safely say that Steam has played a huge part in the recent turn of events. The reports from NPD group reveal that full-game PC digital download purchases reached 21.3 million in the U.S. during 2009, slightly fewer than 23.5 million in retail box sales during the same period. According to these numbers 48 percent of unit sales for PC games last year were digital downloads, and accounted for 36 percent of dollar sales, according to NPD Group estimates.

Although there was a rise in digital sales the overall PC gaming market didn’t grow by that much which has led to a 23% drop in Retail game sales in the US to $538 million for 2009.

NPD also released charts of the top digital retailers based on estimated unit sales and we already know who topped the sales charts for digital downloads. Unfortunately actual sales figure for each site is not available as it would be interesting to know how much does steam account for in number of total digital downloads across all sites. The charts have been divided into two separate categories – frontline (retailers that sell digital games that may or may not be offered at traditional retail) and casual game sites (smaller casual games with try before you buy options and other payment methods):

Top 5 Frontline Digital Retailers in 2009 (based on unit percentage share)

1. Steampowered.com

2. Direct2drive.com

3. Blizzard.com

4. EA.com

5. Worldofwarcraft.com

Top 5 Casual Digital Retailers in 2009 (based on unit percentage share)

1. Bigfishgames.com

2. Pogo.com

3. Gamehouse.com

4. iWin.com

5. Realarcade.com

via Gamasutra