The Windows Store is about to get more Facebook-connected apps. Source: Microsoft

The Windows Store is going to play a much bigger role in Windows 10 than it did in its predecessor. At least, that's Microsoft (MSFT -1.27%) CEO Satya Nadella's goal. In a recent interview with ZDNet, Nadella said that the Start menu will return to Windows 10, and will feature the Windows Store prominently. He said he's bringing back the Start menu "because that's the best way to improve the liquidity of our store. Windows 8 was great except that nobody discovered the store. In Windows 10, the store is right there and done in a tasteful way."

But just a couple weeks before the launch, Microsoft released a new software development kit that enables easy Facebook (META -4.13%) integration with universal Windows apps. The move is being used as an incentive to attract developers that are currently using Facebook's .NET development kit to make desktop apps to instead use Microsoft's SDK to make universal apps.

All about Windows Phone
With Windows 10, Microsoft is introducing universal apps that function across smartphones, tablets, desktops, the Xbox One, Hololenses, and anything else running Windows 10. Microsoft made Windows 10 free for consumers to attract users to the operating system. It knows that more users will attract developers, which is exactly where it's struggling with Windows Phone.

Microsoft currently has just 3% of the smartphone market. The app selection for Windows Phone is minimal, often left as an afterthought for developers that find success on iOS and Android first.

Windows 7, 8, and 8.1, on the other hand, account for over 77% of the global PC market. Many of those users will receive free upgrades to Windows 10 when it becomes available at the end of this month. That's over 1 billion users who might be using Windows 10 within a year. That would be more than iOS. Add in Windows tablets and smartphones and Xbox One users, and the number continues to climb. 

With so many users, developers will be compelled to develop apps for Windows 10. And Microsoft wants to make sure they use its SDK so the apps they make work across all devices. That way, when the desktop app store grows, the mobile app store grows, and Microsoft can attract new customers to Windows Phone.

Good news for Facebook
With Microsoft's new SDK designed specifically to integrate Facebook functionality into Windows apps, Facebook is benefiting from Windows' omnipresence as well. A lot more Windows 10 apps may end up using Facebook for authentication, or adding social elements to applications. That puts Facebook in a position to collect even more data on its users, targeting things like app install ads and other items related to the apps users install on their PCs.

Facebook initially tapped Microsoft to help power its Graph search, but ditched it in December of last year. Now Facebook is focused on developing its own search capabilities in house. But Microsoft doesn't have the option to hold grudges. Facebook controls the most popular API on the web, and developers want an easy way to integrate it into their apps.

Will the Windows Store finally succeed with Windows 10?
Changing users' behavior can be quite difficult, but installing applications from the web is a big pain point for many PC users. The fact that many Windows 8 users still don't use the Windows Store demonstrates a failure to educate the consumer and properly position the app store. Microsoft will be sure to correct those issues with the launch of Windows 10. 

It's a pretty big bet from a company that's used to driving a huge percentage of its revenue from sales of the operating system. If Microsoft fails to attract developers to the platform or consumers to the Windows Store, it will have lost out on a significant amount of revenue from consumers looking to upgrade to Windows 10.

The integration of Facebook into an SDK certainly won't hurt Microsoft's chances with developers. We'll have to wait and see what consumers do.