What: A game by Zynga based on game points and credits that can be used to buy virtual goods for existing games.

Why It Matters: The company makes most of its money through virtual goods sales, as well as advertising and partnerships. Social media analyst Lou Kerner of Wedbush Morgan estimates Zynga's revenue will this year approach $850 million, up from $529 million last year. (via NPR).

Who Should Be Worried: Besides other game developers? Walt Disney and Time Warner, says BTIG Research analyst Rich Greenfield, according to NPR. These games’ popularity is drawing people's away from TV sets, movies and other sources of entertainment. "Media has been fragmenting, and Zynga seems to be doing the exact opposite. It is growing at a staggering rate and reaching eyeballs that none of these companies are doing."

Who Should be Excited: Any advertiser that is interested in virtual goods. The virtual goods market has become a huge ad niche and one, according to an analysis by Flurry last year, that may be overtaking traditional advertising revenues, at least on the iOS platform. It found that during 2010 revenue increasingly shifted from advertising to virtual goods sales until reaching a proportion of more than 80% from virtual goods.

Admittedly, the idea that consumers acquiring virtual swords, gold coins and respect points can outperform advertising seems counter-intuitive, Flurry said. But it points to statistics showing virtual goods sales already represent the primary source of revenue for social gaming on Facebook to back its claim. With mobile social game critical mass now rivaling TV prime time viewership, Flurry anticipates a stronger ad revenue generation through mobile social networking and games in 2011.