Wednesday afternoon, CEO Mark Zuckerberg acknowledged the trend, saying, "There's no argument that Facebook is a mobile company."
The mobile ads users see as they scroll through their news feed are now contributing 23 percent of Facebook's ad revenue, up 9 percent in just three months. The social network is pushing hard to make mobile use fast and appealing.
"Facebook has been making huge strides," tech analyst and blogger Robert Scoble said. "The new app that came out a couple days ago is faster again, and it has more of the desktop features. You can tell they're just working at taking over the mobile business."
Advertisers are making the shift too, even though they have less space to catch the eye of Facebook users.
"It's by far and away the fastest growing segment of advertising," Randy Basso said.
Basso is executive vice president at San Jose's Liquid Agency, which helps companies develop their brand image across multiple platforms.
The prize is billions of dollars in ad spending, expected to hit $11.4 billion this year according to Gartner Research.
Even skeptics may change their tune if Facebook continues to see its mobile ad revenue grow. The eyeballs are there with about two-thirds of Facebook's monthly users connecting via mobile devices.