Top 5 Frontline Digital Retailers -2009 (based on unit % share)

Top 5 Casual Digital Retailers - 2009 (based on unit % share)

NPD Group claimed Wednesday that full-game PC digital download purchases reached 21.3 million in the U.S. during 2009, nearly even with 23.5 million physical unit buys, signifying an important shift in purchasing habits.The tracking firm said that, according to its estimates, PC digital downloads represented 48 percent of unit sales for PC last year, and accounted for 36 percent of dollar sales.Retail sales of PC games declined 23 percent in the U.S. to $538 million in 2009, NPD reported in January this year. As online sales from downloadable content, full game downloads, subscriptions, microtransactions and mobile continue to increase, NPD is looking at ways to measure the impact of those emerging models on a regular basis.Social gaming on networks such as Facebook also are bringing in new gamers who are willing to spend big money on virtual items.developer Zynga alone is on track to bring in a projected $1 billion for 2010, according to recent reports -- and those revenues are going under NPD's monthly sales radar.A recent Gamasutra analysis estimated that NPD's monthly U.S. retail sales reports may have overlooked $2 billion in non-retail revenues in 2009, or about 20 percent of the total reported industry sales for the year."The popularity of social network gaming increased from Q3'09 to Q4'09 as 4.8 million more people played games on a social network in the U.S.," said NPD game analyst Anita Frazier. "This demonstrates how consumers can now experience casual types of games through myriad vehicles, broadening the competitive landscape."NPD also cited a 30 percent increase in iPhone and iPod Touch usage as gaming devices from Q2 2009 to Q4 2009. The firm said 97 percent of people who downloaded a game app last year also downloaded a free version of a game.Additionally, NPD estimated ranks for the top digital retailers in the areas of frontline (retailers with a focus on games also offered at physical retail) and casual (focus on smaller games with a try-and-buy or ad revenue model).1. Steampowered.com2. Direct2drive.com3. Blizzard.com4. EA.com5. Worldofwarcraft.com1. Bigfishgames.com2. Pogo.com3. Gamehouse.com4. iWin.com5. Realarcade.com