NEW YORK ( TheStreet) -- Hey Microsoft ( MSFT), if you're in the car check the rearview mirror and move into the right lane. It looks like there is a laptop freight train called Google ( GOOG) that's about to pass you in sales. I just checked Amazon's laptop bestseller-list, and among the top 17 laptop sellers there are four Google laptops, including the No. 2 seller. No. 1 is Apple's ( AAPL) 13-inch MacBook Pro. Four out of the top 17 best-selling laptops isn't bad for Google after being on the market for only three weeks. These Google laptops are the so-called Chromebooks, based on the Chrome OS, and they cost from $350 to $500. I have written about these extensively starting in early December 2010, including an article in March. Of course, Google doesn't produce the hardware, just as Microsoft doesn't. Initially, Samsung and Acer have models in the market, but they are sure to be followed by others in the coming months. What makes this even more impressive is that Acer's Chromebook won't even start to ship until July 11, but it's selling so well that it's Amazon's No. 17 best-selling laptop as of this writing. The only two U.S. purveyors of the Google laptops thus far are Amazon ( AMZN) and BestBuy.com. As far as I can tell, they haven't even reached Best Buy's ( BBY) stores yet, but I obviously haven't checked more than a small number of Best Buy stores. They are only available for purchase online, sight unseen. It's even more impressive, then, that they are selling so well. Who is buying the Google laptops? Let's first stipulate who is not buying them -- the general population. Most people, even those who live in Google's Mountain View, Calif., zip code, haven't even heard of the existence of a Google laptop. Corporations, schools and other government entities are probably buying them in the hundreds of thousands. If you have converted at least some of your staff or students to Google Docs and Gmail, moving them away from expensive-to-maintain traditional laptops based on Microsoft and Apple is a no-brainer. The life-cycle cost savings are dramatic, and dwarf any quibbling of whether or how much cheaper a Chromebook is to buy on day one.