GM is reportedly launching a mobile-only advertising campaign on Facebook for the Chevrolet Sonic that sees the automaker investing in the social network for the first time in almost a year.

The second largest U.S. marketer famously pulled all of its advertising from Facebook last year shortly before the social network made its initial public offering. While GM?s departure played a role in Facebook?s rocky second half, the automaker has reportedly decided to return to Facebook following numerous refinements of its advertising offerings, particularly on the mobile front.

?ComScore shows that 24 percent of time on android and iOS mobile devices is spent using Facebook,? said Sebastian Gard, senior vice president and director of social media and strategy at Arnold Worldwide, Boston. ? That's almost three times higher than the next most used app ? iTunes.

?So in reality, Facebook ads are the only sustainable, scaled ad play on mobile right now,? he said. ?For brands that have built the value of Facebook engagement into their ROI models, that's actually great news since Facebook's native ads like Sponsored Stories perform especially well on mobile in our experience.?

On target
GM was reportedly lured back to Facebook in part because of newly available targeting and measuring capabilities, according to a story in Ad Age.

The automaker is supposed to be launching a mobile-only campaign on Facebook, showing how brands are more focused on mobile these days and are no longer bringing it in as an afterthought.

However, a mobile-only approach has its challenges since consumers are engaging with brands across multiple screens.

?Mobile-only is not for everyone and I expect to see it where it makes sense,? said Craig Elimeliah, vice president and director of creative technology and digital solutions at RAPP, New York. ?But doing it for the sake of doing it will result in less than desirable returns.

?If the nuances around the communication aren't native to the platform or channel it will fail miserably,? he said. ?Not many brands know what these nuances are yet.

?Understanding context in real-time requires taking risks, and big brands don't like to take risks. Mobile and social are very tightly intertwined and require a certain transparency and truthfulness in the value offered either through content or utility. Not an easy solve but exciting challenges to take.?

Back to center
Mobile advertising plays a crucial role for Facebook as its user base increasingly migrates to smartphones and tablets to socialize. Advertising is also Facebook?s primary source of revenue.

However, the company?s initial efforts in mobile advertising were not met with a lot of enthusiasm. In part because of this and in part because of brands? challenges with leveraging the convergence of mobile and social media, last year it looked like marketers were not driving the kind of results they were hoping for via Facebook advertising.

After GM?s departure and Facebook?s lackluster IPO, the social media redoubled its efforts and has been consistently introducing new and updated mobile advertising refinements, including better targeting capabilities.

?In general, interest-based targeting and Facebook Exchange have created a perception of much richer targeting, and have also demonstrated strong results in engagement levels,? said Nathaniel Perez, Miami-based global head of social experience at SapientNitro.

?We've all seen at one point or another a sponsored, targeted brand post in our feeds, with whopping engagement numbers right below,? he said.

?In the case of the Sonic demographic, and for the mobile Facebook demo in general, sponsored content is a powerful and natural ? for now ? way to go to promote engagement with a hyper targeted audience.?

Most recently, Facebook enhanced its mobile app install ads so that marketers can reach specific versions of Android and iOS mobile operating systems as well as devices on Wi-Fi only connections (see story).

Facebook also recently introduced Home for Android, which could eventually be heavily ad supported (see story).

GM?s return suggests advertisers are taking a second look at Facebook mobile.

?We are seeing the pendulum swing back towards center,? said David Hewitt, Atlanta-based global mobile practice lead for SapientNitro.

?The market went through the rush to make all things social and have a Facebook widget for everything to the over reaction phase of filtering out the marketing initiatives that can't be as directly tied to sales,? he said.

?Now brands are seeing that social is a core component of the mix and often an ingredient to more thought-out connected campaigns and less of a commodity item in the overall media plan.?

A rising star
The return of GM is the latest example of how Facebook?s mobile advertising star is rising rapidly this year.

EMarketer recently forecast that Facebook will earn $1.53 billion in mobile advertising revenue worldwide this year, up from just $470.7 million last year.

Mobile advertising is expected to account for more than 27 percent of the company?s global ad revenue, up from 11 percent last year and zero in 2011.

"Of course the challenge is that th

"Brands like to have a lot of space to make an impression, mobile has certain constraints there but Facebook has made the required changes to their newsfeed  that will support the type of ads brands are looking to deliver," said Marc Poirier, co-founder and executive vice president of business development at Acquisio, Brossard, Canada.  

is will be a learning process and GM will need to keep their focus and figure out for themselves what the media has to offer and how to find success in this new environment," he said.

Facebook is currently the No. 2 mobile ad publisher, by revenue, in the United States behind Google.

More big brands such as GM could soon be headed to the social network as agencies, too, take notice of the opportunity.

?We are seeing the major agencies who represent the big brands diving in much deeper on mobile across the board, with Facebook being a significant mobile channel,? said Howie Schwartz, CEO of Human Demand.

?Facebook has been doing a really great job in testing and rolling out new mobile ad units and native formats, which will continue to increase interest in advertising and testing on Facebook mobile,? he said.

Final Take
Chantal Tode is associate editor on Mobile Marketer, New York