This has been an issue that has been plaguing Facebook for some time now. During the company's pre-IPO road show this past spring, investors and analysts raised concerns about how Facebook will generate revenue from the growing number of users who are accessing the social network via their mobile phones and tablets from cafes, gyms and town parks.

And in a filing with the U.S. Securities and Exchange Commission, Facebook admitted that users' shift from traditional desktop or laptop computers to mobile devices was hurting the company's advertising plan. In the filing, the company also noted that it had no way to monetize the growing mobile trend.

Facebook even listed mobility as one of its pre-IPO "risk factors."

Shimmin said Facebook needs to tackle mobile advertising very carefully.

"In some ways it's a real estate issue and an expectation issue," he said. "When you're sitting at your desk... it's easier to swallow the advertising that's in front of you. But that gets in the way when you try to translate that experience to the mobile platform with a smaller screen and people on the go. This can be a very dangerous game to play. Every advertisement takes away from the usability of your product."