Last week, Barnes & Noble (NYSE:BKS) made a seemingly small announcement that made a huge difference to its customers. The announcement was that the Nook will now allow access to the Google (NASDAQ:GOOGL) Play store. What it really means is that the Nook is now an almost fully formed Android tablet. That's going to be huge for Barnes and Noble.

Read any Nook, Kindle, and Nexus comparison and you'll see something like this: "The problem with the Nook HD's locked-down operating system is that it does not enable installations of applications that are not downloaded from Barnes and Noble's marketplace/store." What you won't see is list of shortfalls in the technology itself. Engadget's review of the Nook HD+ stated, "From a hardware perspective... it's pretty tough to argue with a 1,920 x 1,280 display on a $269 / $299 device." The new expanded availability of Google Play may just push tablet buyers over the edge.

Why Barnes & Noble opened up
There is absolutely no surprise in hearing that tablets are on the rise. Recent reports have highlighted the fall in PC sales over the last year, and much of that market is shifting to tablets and smartphones. With Microsoft (NASDAQ:MSFT) pushing its Windows 8 operating system, the world is quickly filling up with productive tablets, which could realistically offer a replacement for laptop owners.

Enter the Google Play store. Play offers Android owners a seemingly unending range of programs to run on their tablets, including productivity offerings from Microsoft. By opening up the entire store to Nook HD users, Barnes & Noble turned the tablet into a productive piece of hardware. That means that it can now compete on the same field as the Surface and the other Android tablets.

What it means for Barnes & Noble
That, in turn, is going to help Barnes & Noble get the Nook division firing on all cylinders before it spins it off into a new company. As I -- along with most investors -- have been harping on for a while now, the Nook spin-off is the best thing Barnes & Noble can do right now. Sales of the Nook dropped 26% in the company's last announced quarter, and investors promptly ran for the hills.

But now Barnes & Noble has unleashed the power of Google's storefront while simultaneously putting the Nook on sale for Mother's Day. The combination should hopefully jump-start the Nook sales machine, giving it the momentum it needs to regain the ground that it's been losing recently.

On top of the Google Play access, there's also the possibility that a future Nook could run Windows 8. New, smaller Windows machines have been announced recently, and Microsoft has already dropped $300 million into the Nook business, giving it plenty of reasons to work out new ways to sell more machines.

In short, the move to open up the Google Play store isn't just a good thing for current Nook HD owners, it's a sign for investors. Changes are ahead, and the Nook isn't going to sit on the sidelines while other tablets take all the sales and spotlight.

Fool contributor Andrew Marder has no position in any stocks mentioned. The Motley Fool recommends Google. The Motley Fool owns shares of 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.