Phil Spencer, head of Microsoft Game Studios, has revealed that the fan base for Crackdown, the Microsoft-owned IP, is much larger than sales would suggest.

"We sold 1.7m and if you look at the number of Live users and the pre-owned market there are a lot of people who have put Crackdown in their 360 and played that game - well over two million have played it on Live, and that doesn't include the offline players," Spencer told MCV.

Spencer also said that if Microsoft had wanted it could have put out a Crackdown sequel much sooner, but chose to wait in order to ensure Crackdown 2 is a quality product.

"It would have been easy to chase the money, but I want to make sure that anything we work on has a chance to take hold and gain avid customers to nurture," he explained. "We own the IP and we could have easily just found another developer out there and done something called Crackdown 2 but we wanted it to be special."

Crackdown 2 is in development at Ruffian Games and is scheduled for release on Xbox 360 in 2010.