Surprisingly, out of Amazon's top three best-selling laptops this holiday season, two of them are Chromebooks. Even weirder, according market research company NPD, Chromebooks account for 21% of all commercial US laptop sales so far this year, and 10% of all computers and tablets sold in the US. In 2012, Chromebooks accounted for just 0.2% of all computer and tablet sales. Is this really happening? Is Google doing it again, first with Android taking the world by storm, and now Chrome OS? Is the low-cost, netbook-in-sheep's-clothing Chromebook the surprise breakout hit of 2013?