"For years, online gaming was dominated by subscription games, and to this day games with subscription models can be quite successful (World of Warcraft being the obvious example), but free-to-play is becoming an increasingly attractive business model for game makers. It's already huge in Asia, and more and more Western companies are testing the free-to-play waters these days.
The fact that the games are indeed free makes them quite enticing to potential players. The trick is to properly monetize these games with advertising and micro-transactions. Incentivizing players to not only stick around and keep playing, but also to regularly purchase virtual items to enhance their experience is key.
Just entering the free-to-play market hardly guarantees success. How did games like RuneScape (over 100 million active accounts), MapleStory (over 50 million players worldwide) and Perfect World International (over 50 million players worldwide) do so well? In this special feature, Perfect World Entertainment provides tips on how to succeed in the burgeoning free-to-play field."