Zynga’s Empires & Allies has amassed over 40 million users in under four weeks time. This means the game now surpasses the venerable FarmVille in users.

Zynga s most popular title CityVille has 88 million users on Facebook, while the company’s total active users had grown from 249 million to 269 million in two short weeks. This growth and ability to produce constant hits will likely benefit the company if and when it decides to file for an IPO.

Source: VentureBeat