Zynga, known for FarmVille and other Facebook games, is reaching for the sky with ambitions to be as ubiquitous in the game world as Google is in the search world. Its slogan is "Connecting the world through games."
Zynga is releasing apps to reach the mobile audience and expanding its line with instantly popular FB games such as FrontierVille which, after a month, has already attracted 20 million users. With so many players, Zynga has great potential as an advertising medium (see interview with Zynga's founder here).
However, the New York Times points out that Zynga's traffic dropped a bit after Facebook restricted some of the Zynga messages related to game usage ("Look! I found a pretty, purple, polka-dotted pony that needs to be petted/fed/watered/walked/brushed!").