Just shy of 50 million unique users play Zynga's Facebook game CityVille every month, the developer has revealed.
As detailed by VentureBeat, the game has 49.7 million monthly active users, with over 10 million playing the game every day. During peak hours, as many as four million players are logged on at the same time.
That makes it the most popular game on Facebook by some margin, with Zynga stablemate FarmVille coming in second with 30.9 million monthly users. EA's The Sims Social is third with 30.4 million.
41 per cent of CityVille players are male, 53 per cent female and six per cent "undetermined". The average user enjoys five play sessions per day.
This week Zynga announced plans for a stock market flotation, with the California-based outfit valued at around $9 billion.