Facebook says it doubled its mobile advertising revenue in the fourth quarter of last year from the previous three months.
That is a sign the top social network is addressing the problem of more of its users migrating to smartphones and tablets.
Investors want to see evidence that chief executive Mark Zuckerberg is delivering on promises to develop a full-fledged mobile advertising business.
But the growth was not as good as some on Wall Street had wanted to see and Facebook’s share fell.
Its net income in the fourth quarter was 64 million dollars, compared to 302 million dollars a year earlier.
Facebook has rolled out a wide variety of new services in recent months as the company seeks to stay ahead in the fast-moving Web market and to convince Wall Street that it can turn its audience of more than one billion users into a sustainable business.
Zuckerberg said the company plans to spend heavily to recruit talent in 2013 as the company pushes forward with new product development, particularly “mobile-first” services.
“We aren’t operating to maximise our profit this year but we’re doing what we think will build the best service and business over the long term,” Zuckerberg said during a conference call with analysts.