We already knew that Microsoft Corporation had to write-down $900 million in excess of Microsoft Surface inventory for the fiscal fourth quarter. In Microsoft’s 2013 10-K SEC filing, the company projected that revenues of the Microsoft Surface reached around $853 million in revenues. This means that the company’s inventory adjustment was larger than the sum total of all Microsoft Surface sales. Microsoft also spent a lot of money marketing the Surface. The company saw an $898 million increase in advertising costs associated with Windows 8 and the Surface.