Gamasutra - News - League of Legends Sees 1.4M Daily Active Players, 15M Total Registered: "Riot Games has revealed that its action RTS title League of Legends sees more than 1.4 million daily active players, with over 15 million players now registered.
The developer also noted that the current number of active players each month is now over 4 million, with the peak number of simultaneous players across its U.S. and European servers topping 500,000."