The publisher of Anarchy Online, Funcom, has used revenue from billboards in Anarchy Online to subsidize a basic version of the game for free over the Internet, said Terri Perkins, a Funcom product manager. It also has used the money to develop expansions to the Anarchy Online fantasy world that players can pay extra for.

Other video game makers, however, are concerned that adding advertisements to their creations will alienate customers used to escaping into science-fictional and Tolkien-esque digital worlds far from the reach of Madison Avenue.

"We're not going to paint a Nike swoosh on the side of the castle of Qeynos," said Chris Kramer, a spokesman for Sony Online Entertainment Inc., the publisher of EverQuest, an Internet-based game set in a swords-and-sorcery fantasy world. "That's the sort of thing that would really turn off the player."