Zynga, the maker of such games as 'FarmVille' and 'FrontierVille,' is valued at $5.51 billion, according to SharesPost Inc., an exchange for shares of privately held companies. Electronic Arts, the second-largest game publisher by sales, is worth $5.22 billion on the Nasdaq Stock Market.
Started by Mark Pincus almost four years ago, Zynga has become one of the fastest-growing technology companies by using Facebook Inc.'s social network to distribute games. It makes money by selling virtual goods, such as vehicles and weapons that help players advance in games. The company has grabbed about a third of that market, which is worth $1.6 billion this year, according to Inside Network in Palo Alto, California.

Zynga is impressive, no doubt, and Pincus has been masterful at building and promoting his company. But I smell a bubble. What do you think?

(Hat tip: Techmeme.)