What you need to know: The social networking giant continued to ride a strong mobile ad business to $3.85 billion in quarterly revenue — an increase of 49% from $2.6 billion during the same quarter a year earlier. Facebook’s quarterly profits totaled $701 million, or 25 cents per share, representing a 34% year-over-year increase.

Once again, Facebook (FB) got a bulk of its revenue from mobile ads as it surpassed analyst expectations of $3.7 billion in revenue. Facebook’s sales have grown by about 60% in each of the previous two quarters with much of those gains attributed to mobile ads. Despite topping analysts’ forecasts, Facebook’s fourth quarter saw the company’s slowest rate of quarterly sales growth since early-2013 and the company’s shares dipped slightly in after-hours trading.

The company also provided full-year financial results, showing a 58% bump in annual revenue, to $12.5 billion, and $2.9 billion in profits — nearly double 2013’s profits.

“We got a lot done in 2014,” CEO Mark Zuckerberg said in a statement. “Our community continues to grow and we’re making progress towards connecting the world,”

The big number: Facebook ended 2014 with 1.39 billion monthly active users (MAUs), which was up 13% from 2013. Mobile MAUs grew by 26% in 2014, to 1.19 billion.

Facebook’s expanding mobile ad business, which has shown huge gains over the past couple of years, represented nearly 69% of the company’s $3.6 billion in ad revenue. Ad sales were up 53% from last year’s fourth quarter, when mobile ads accounted for only 53% of overall ad revenue.

What you might have missed: In October, Facebook’s tumbled slightly following the company’s third-quarter earnings report after the company announced plans to dramatically increase the company’s spending on hiring and acquisitions in 2015. In the fourth quarter, Facebook said, the company’s capital expenditures rose 7%, to $517 million.