Zynga has seen early success with its latest venture CityVille as over 26m users have signed up to play it.
The casual Facebook game – which allows users to create and run their own city – went live on December 2nd. It currently has 26,614,646 monthly active users on Facebook putting it just 2m behind FrontierVille.
CityVille is free to play but allows users to purchase in-game currency in exchange for real money.
Zynga was founded in July 2007 and has since released a string of casual browser-based games including FarmVille which has over 55m users.
The firm has also launched iPhone apps including Live Poker and Mafia Wars.