According to a preliminary estimate released by NPD, total consumer spending on all video game content in the US was between $15.4 and $15.6 billion during 2010. That figure includes physical console and PC games, digital downloads, used games, rentals, subscriptions, social network games, DLC, and mobile game apps. Assuming the initial data is correct, the research firm believes overall sales have fallen by about 1% from 2009.

Although retail games accounted for the majority of spending with $10.1 billion in revenue, sales dropped 5% from $10.6 billion in 2009. PC game sales increased by 3%, and that's no surprise with blockbusters like StarCraft II and WoW: Cataclysm breaking records last year. That, combined with increased spending on downloads, mobile games and other segments offset the declines in physical sales, rentals and subscriptions.

"The increasing number of ways to acquire the content has allowed the industry to maintain total consumer spend on content as compared to 2009, and we should expect 2011 to be a growth year in the games industry as the consumer demand for gaming continues to evolve," NPD said. The outfit expects to release a final estimate of consumer spending in March's "Games Industry: Total Consumer Spend (2010)" report.