The Microsoft (MSFT 1.58%) Surface has been viewed as a bust, particularly after a $900 million write-off in the second quarter of the year. But few point to the fact that Microsoft has gone from almost no market share in tablets and smartphones to a growing, albeit small, market share in the second quarter. The company now commands 4.5% of the tablet market and 3.7% of smartphones, and with more devices hitting shelves every day, contributor Travis Hoium thinks the company still has upside in the mobile business.