Trion Worlds' debut MMORPG RIFT has made a big splash in the market. Trion SVP of publishing David Reid revealed on Tuesday that the game has sold almost one million copies in its first three months.

Sales of the game itself are important, but the game's fate will be decided by whether players continue to subscribe. Reid told Gamasutra that the retention rate for Rift is strong, though.

"We're really pleased with what we're seeing. And beyond that, it was a pleasure to see that in the latest Activision Blizzard earnings call, they inquired about Rift when Blizzard announced that [World of Warcraft's] subscriber numbers went from 12 million to 11.4 million," said Reid. "You can do some math... we know very well where those 600,000 people are."

Obviously, RIFT's subscriber base is nowhere near the size of WoW and probably never will be. However, they don't need to be. There's always talk about how some new MMO is going to "kill WoW" but the fact is, you don't need to kill it to succeed in the MMO market. Plenty of companies can - and are - doing quite well even with only a fraction of WoW's subscriber base.