Microsoft has reportedly spent more than $1.5 billion to market its new operating system, Windows 8, and accompanying mobile device, the Surface. But the messaging seems to be lost on prominent app developers.

Despite offering more lucrative revenue splits for app developers than competitors Google and Apple, many of the largest digital media properties in the U.S. and makers of the most-popular tablet apps have decided that developing apps for the Surface -- and the Windows app store in general -- is not yet worth their time.

The most glaring omission is Facebook, a company that Microsoft invested $240 million for 1.6% stake in 2007.

"That's a bad thing," said Ray Velez, chief technology officer of digital agency Razorfish. "But Facebook doesn't have the greatest track record. They are really hard to work with."

Facebook's absence from the Windows app store is even more curious considering many of the Surface's preinstalled apps -- Internet Explorer, Maps and Weather, among others--are integrated with Microsoft-owned Bing, the search engine that 's integrated with Facebook.

"We are constantly evaluating our strategy for supporting new platforms ... as the market and consumer adoption evolves," a Facebook spokeswoman said in a statement.

This tech PR parlance generally translates to there not being enough Surface users for Facebook to justify developing an app for the platform.

"It's the exact same challenge that happened with Android and Google Play," said Marci McCue, head of marketing for Flipboard. "It's a new type of user and you really have to think about the way [the device] is used."

Ms. McCue added that Microsoft approached Flipboard two months ago about it possibly developing a version of its popular magazine-style news aggregation app for the Surface. But rather than develop an app for Windows, the company has opted to focus on new iterations of its iOS and Android offerings.

Instead of concentrating on developing a Surface audience, Flipboard wants to improve the app experience for its iPad and Android device users.

Flipboard is not alone. Some of the most mobile-centric digital media companies in the U.S. have also shirked building apps for the Surface.

A recent study by digital research firm ComScore ranked the 30 most highly trafficked digital-media properties based upon unique viewers across all platforms: laptops, PCs, smartphone and tablets.

Pandora and Twitter receive 81.1% and 53.6% of their U.S. traffic from mobile devices, making them the two most mobile-centric media properties in the country, according to ComScore. Yet, neither company has an app available for the Surface.

Neither does Facebook, which came in at No. 3 on the overall ranking with 178 million unique viewers, 51% of whom access the social network via mobile. Other notable omissions from the Windows app store include Amazon (45.9% of uniques from mobile devices), Yelp (47.6%), Spotify, Pinterest and Instagram.

All of those properties have apps available on both the iPad and Android devices. In fact, the Pinterest and Amazon iPad apps ranked in the top 25 free iPad apps in the Apple App Store as of November 29. Facebook, Pandora, Instagram, Twitter and Pinterest all ranked in the top 25 free apps in Google Play.

Developers' reluctance to build on the Surface is in spite of Microsoft offering revenue splits that are more favorable for app creators than Apple and Google. Apple and Google take 30% of all money earned from apps sold in their stores or in-app purchases made on their platforms. Microsoft offers the same 70-30 split until a company earns $25,000 in revenue from the Windows app store. After that , developers get to keep 80% of app revenue.

But thus far, the top-earning app shops have not been interested.

Of the 10 app publishers that earned the most revenue on iOS in October according to app analytics firm App Annie, only one shop, Gameloft, currently has at least one app available for the Surface. Gameloft is also the only top-10 earning publisher on Google Play during October with an app on the Surface.

One explanation for the absence of certain popular apps is that Microsoft did not release its finalized software development kit until September.

"That's not a lot of time to build a complicated app," Mr. Velez added. "The top 100 apps should've been a higher priority. That might have been a little bit of a miss, but I don't know if anyone could've done much better."

A Microsoft spokeswoman emphasized that the app store's advantage has been quantity if not quality. She pointed out that the Windows app store launched with more apps available than any other app store had at its opening, and the number of apps available has already doubled since late October.

While sparse, there are some big name app titles for the Surface.

Google, Yahoo, AOL, eBay, the New York Times, ESPN and the Weather Channel ranked in the top 30 in ComScore's multi-platform index and each property has at least one app for the Surface. Twitter said it is currently developing one and hopes to have it released in the coming months. Pandora, meanwhile, is creating an app for Windows 8 phones, but not for the Surface.

Ms. McCue, for one, is confident that the dearth of Surface won't last.

"They're pressing hard [to attract developers]," she said. "They're going to make some progress."

Microsoft's Surface is still missing key apps: