"When were first going to make World of Warcraft, we wanted to make it free and advertising supported," Pardo said. "We didn't want to charge a subscription, but as we researched market conditions, we realized that wouldn't support us."

World of Warcraft has amassed roughly 10.7 million subscribers since its initial 2004 launch, marking the title as the most successful MMO of all time.

Though free-to-play titles have seen great success in overseas markets, the business model has yet to catch on in the mainstream North American industry. However, several upcoming titles—including EA DICE's Battlefield Heroes—show a steadily increasing interest in alternative sales strategies.