Social games powerhouse Zynga has entered the increasingly competitive world of virtual slot machine gaming with the launch Friday of Zynga Slots. Zynga aims for the mobile market: the game is only launched for iOS and not on Facebook or on its Zynga website.
Zynga’s new slots game follows the developer’s previous launches of Zynga Bingo and Slingo, another bingo game but with slots-type features.
Leading social games developers have been drawn to casino-type content as virtual casino games are considered to have both higher monetization rates and player retention rates than many other genres of virtual currency gaming. Zynga Poker recently became the most popular game on Facebook when surpassing both FarmVille and CityVille.
Other sources: http://www.gamblingcompliance.com/node/49372