In the tech sector, mobile devices typically receive most of the attention. But in 2013, Google (NASDAQ:GOOGL) powered Chromebooks deserve a bit of attention as well. According to NPD Group data, Chromebook sales accounted for 21% of all preconfigured notebook sales in the U.S. this past year -- up from a "negligible" share in 2012. Those numbers indicate that the PC industry is still very much in a state of transition.

Chromebooks

Chromebooks. Source: Google

Chromebooks are a very small part of Google's overall business, so while Google investors should be pleased with the current success of the devices in the market, it won't make much of a difference to the company's bottom line. But as Chromebooks have moved from an obscure computing option to a mainstream contender, Google's endeavor is important for Apple (NASDAQ:AAPL) and Microsoft (NASDAQ:MSFT) investors to watch.

That's because the NPD data showed that preconfigured Windows notebook sales didn't have any growth compared to last year, and combined sales of Apple's notebooks and desktops dropped by 7%. Besides a 10% increase in Windows desktop sales, there doesn't seem to be much for Apple and Microsoft to be pleased about when it comes to computer sales.

But those numbers don't paint the entire picture.

While Chomebooks have certainly made some gains, Apple's strength lies in its iPad lineup. While the company's desktop and notebook computer sales were down, that's to be expected as more consumers opt for tablets. Where things start to get interesting is when and if Apple decides to blend some of its notebook power into its iPad to create an entirely new product that merges both hardcore computing needs of users and the portability of a tablet. Others companies have tried hybrid devices, but Apple may be just the company to actually pull it off.

For Microsoft, the outlook is less defined. Though the company just revamped its Surface tablet lineup, sales of the new Surface 2 have yet to be released. Some early reports showed that the devices were sold out during the holiday season at some locations and on the Microsoft store website, but without hard data it's hard to know whether the tablets were a success or that Microsoft made fewer devices available. But Microsoft has proven that it's committed to revamping Windows for a more mobile era with the Surface and now the Surface 2. Next year will bring the results of Microsoft's moves into a clearer focus, and investors will hopefully see a glimmer of success. 

Why all of this matters
Rehashing the PC vs tablet theme could seem a little old as we head into 2014. But it's worth noting because the change from desktops and notebooks to tablets isn't happening overnight. As consumers move toward tablets, new opportunities are opening up for device makers. For example, though Apple has a strong grasp of the tablet market, Google's Android has obviously dominated in the space as well. That's been good for companies like Samsung who have adopted the Android OS into its tablets, as well as selling Chromebooks.

The PC market is still in transition, and there's still plenty of room for Apple, Microsoft, Google, and others to come up with innovative ways to sell new devices to consumers. It's simply up the companies to decide how they'll navigate the next few years of transition.

Fool contributor Chris Neiger has no position in any stocks mentioned. The Motley Fool recommends Apple and Google. The Motley Fool owns shares of Apple, Google, and Microsoft. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.