"If you"re a game publisher and and you are not looking into this new market and this new business model, you are becoming a dinosaur," IDC analyst Billy Pidgeon said in the April 28 print edition of Forbes, which tackled the rising free-to-play games market.

It"s the smaller companies that are innovating most in this area, such as Nexon America, creators of the free MMO MapleStory, Focus creators of Trackmania Nations Forever, Jagex with RuneScape, and Acclaim, which has a full slate of free-to-play games.

Other companies such as WildTangent and GameTap (part of not-so-small Turner) act as portals where gamers can access multiple free titles.

But the "traditional" mega game publishers are also now testing the waters of the free-to-play model. Electronic Arts is doing it with the action title Battlefield Heroes (and has been in the free-to-play online casual space with Pogo for years), THQ is releasing a free-to-play online-only version of Company of Heroes in China, and established online game makers like Sony Online Entertainment and NCsoft are expanding their free-to-play efforts.

The term "free-to-play games" is a bit of a misnomer, as the games often make their revenues with virtual item sales and advertising. But the core games are free, and the low barrier of entry is particularly attractive to a younger audience.

"If you are just selling software in a box, your time is limited. The growth potential is much more exciting on the Internet," Pidgeon added.