Facebook has released fourth quarter and full year financial results for the period ending December 31, 2012. The social network reported $1.59 billion in revenue, topping Wall Street estimates with a healthy 40 percent year over year increase. Profit, however, was down a whopping 79 percent as the company spent heavily during the quarter to build their mobile advertising division.

Specifically, profit tumbled to just $64 million for the quarter once the $1.06 billion in costs and expenses were factored in but that had little effect on Facebook's founder. Zuckerberg said 2012 was a big year for the social network, especially with regards to mobile. There are now more people using the service on mobile than through a desktop, he revealed. As such, 23 percent of the site's total revenue came from mobile apps in the quarter.

At the end of the year, the company claimed to have 1.06 billion monthly active users and for the month of December, Facebook averaged 618 million daily active users. Broken down further, some 680 million people accessed the social network from a mobile device last month and on New Year's Day, 600 million people uploaded photos to the site. For December, 59 percent of users logged into the service on an average day.

Facebook also addressed user-promoted posts and Gifts, saying that both categories returned very small amounts of revenue. These divisions aren't expected to grow dramatically over the long run.

The plan moving forward is to continue to hire aggressively and finish building existing products which is expected to increase expenses by at least 50 percent.