Microsoft's fabulously successful Xbox ... ?
Successful? The Xbox part of the company didn't turn a profit in its history until this year, and if Microsoft wouldn't have been able to leverage its existing monopolies in the software marketplace to keep the Xbox folks on life support for seven years, it never would have.
Not only that ... while the Xbox 360 is arguably a nice piece of hardware, it's locked down to the point where most users don't care even comtemplate adding third-party hardware without risking having their XBox Live accounts blacklisted.