The next time you hear Steve Ballmer saying that he wants Microsoft to succeed in the mobile market, do not doubt his sincerity.  A proxy statement released by Microsoft yesterday revealed that Ballmer essentially lost $670,000 due to the company’s poor performance.

A little background information: like many companies, Microsoft tries to incentivize its execs.  And for fiscal year 2010, Ballmer could have gotten a bonus worth as much as 200 percent of his base salary, according to the proxy statement.

However, after the Compensation Committee and certain members of the Board of Directors considered "the unsuccessful launch of the Kin phone; loss of market share in the company’s mobile phone business; and the need for the Company to pursue innovations to take advantage of new form factors," Microsoft gave Ballmer a bonus of $670,000, not $1,340,000.

That’s got to sting a bit, and perhaps make him all the more eager to make Windows Phone 7 competitive with Android and iOS.

Of course, we don’t mean to suggest that anybody should feel too bad for Ballmer.  All in all, Ballmer received $1,351,121 for the fiscal year ending June 30th, and that’s quite a lot of money.  Also, Forbes recently named the 54-year-old the fourteenth richest American, with a net worth of $13.1 billion.

It should be interesting to see if this development provokes Ballmer into adopting a different approach to the mobile market, anyway.