Facebook addressing its mobile uncertainties

Nearly half of Facebook's more than 900 million users access the site through a mobile device, Mashable reports. Its mobile iteration had previously been ad-free until this week.

Facebook has included the option for marketers to add Sponsored Stories to users' mobile news feeds, building upon the ad platform that was introduced in January 2011 for desktop use.

Marketers can now buy Sponsored Stories specifically tailored to users' mobile devices, although unlike with desktop ads, they can't specify where the ads are placed. Advertisers also have the option to purchase combined placements in both desktop and mobile.

The move corresponds directly with Facebook's recent IPO, which had many investors citing the social network's lack of mobile influence as a "potential impediment to the company's revenue prospects," notes the media outlet.

The New York Times adds that Facbeook looks to address its mobile issues further by eventually releasing a branded smartphone. The company has already hired more than half a dozen former Apple software and hardware engineers who worked on the iPhone and iPad for guidance.