Dec 13, 2010 15:02 GMT  ·  By

Despite some claims that the social gaming world is somehow not seeing the kind of growth and numbers it once did, it looks like each Zynga launch is bigger than the previous. Zynga's latest game, CityVille - a name which, apparently, is meant to be taken seriously - has seen the kind of growth that puts the company's previous superstars to shame. Eight days in, CityVille already had six million, doubling its audience in two days.

Facebook lists the app at over 22 million monthly active users, but that's just an estimation based on how many users have played so far.

AppData, a site dedicated to keeping track of Facebook app usage, lists CityVille as having 8.5 million daily active users and 13 million monthly active users at this point.

CityVille is Zynga's most advanced game to date, but doesn't stray too far from the perfected formula. The "Ville" in the title says it all, it continues the legacy of FarmVille and the newer FrontierVille. The gameplay relies on the same mechanics, though it adds a bit of city planning to the mix.

The success of the game, at least initially, doesn't really rely on the gameplay as much as on Zynga's marketing machine. The company did't hold back in promoting its latest title and it shows.

In the first 24 hours since launch the game gained about 300,000 users. FrontierVille raked in just close to 120,000 in the first day. A week later, CityVille had about three million daily active users.

Already, CityVille was Zynga's fastest growing game to date, by a significant margin, but it kept on growing. Just a couple of days later Zynga said that the game reached the six million daily active users. It remains to be seen if it can continue to grow at this pace, but it doesn't look like Zynga has anything to worry about for the foreseeable future.