As many as 400,000 unlocked iPhones were running on China Mobile’s cellular network at the end of last year, according to market research firm In-Stat.

Apple sold 3.7 million iPhones in 2007, and more than 10 percent of them are in China, In-Stat said, attributing that information to China Mobile. That helps explain part of the “iPhone gap” created by the difference between Apple’s shipping totals for 2007 and the activations reported by its carrier partners in the U.S. and Europe.

Somewhere around 1 million iPhones are thought to have been unlocked, and 400,000 are in China.

Despite Apple’s attempts to keep iPhone unlocking under wraps with new software and changes to the iPhone’s bootloader, enterprising entrepreneurs are apparently giving the people what they want. This is a bit of an opportunity lost for Apple, since the company has signed lucrative revenue-sharing deals with its carrier partners that don’t apply if an iPhone is unlocked from its respective network.

Via news.com