While Microsoft (NASDAQ:MSFT) may have come from a position of relative obscurity in the smartphone arena, recent reports show that its Windows Phones are starting to get traction. The big percentage increases in the company's share of U.S. smartphone sales, driven mostly by sales of the Nokia (NYSE:NOK) Lumia, are not a sign that Google (NASDAQ:GOOGL) or Apple (NASDAQ:AAPL) need to get worried, but they are significant. As Microsoft battles BlackBerry (NYSE:BB) to be the No. 3 operating system, sales are critical.

In the video below, Fool.com contributor Doug Ehrman discusses the numbers, what they mean and what they don't, and how they position the company for the rest of 2013.