It has been a roller coaster year for Facebook, and for the companies that have bet at least some of their marketing, communications, customer service and e-commerce budgets on the social network.

There's no argument that the biggest moment in Facebook's year was its May IPO, although it did not go as Facebook hoped. With shares widely considered to be overvalued and technical glitches related to trading out of the gate, the IPO was a dud. The stock price has rebounded somewhat since then, but Facebook is still struggling to find its footing in terms of how it will make real money for shareholders.

Another big moment in Facebook's 2012 history was its purchase of Instagram. People questioned whether the company was worth the $1 billion Facebook offered to pay in April, but the acquisition (totaling $730 million upon completion, based on Facebook's stock price) certainly cemented the importance of photos and mobile photo sharing to social networks.

Since the acquisition was originally announced, early in the year, there has been a bit of a dust-up in Instagram-land. New terms of service seemed to indicate that the company could sell users' digital photos for social advertising. Instagram co-founder Kevin Systrom has acknowledged that users are upset and in a blog post attempted to clarify some of the confusion about Instagram's new terms of service: "Our intention in updating the terms was to communicate that we'd like to experiment with innovative advertising that feels appropriate on Instagram," he wrote. "Instead it was interpreted by many that we were going to sell your photos to others without any compensation. This is not true and it is our mistake that this language is confusing."

Other events on Facebook's 2012 timeline were less impactful. Facebook Stories, where people tell how they are using Facebook in innovative ways, didn't seem to make much of a ripple. And Facebook Gifts, a feature that lets users buy and proffer (virtually, anyway) products through Facebook, was met with disinterest at best and derision at worst. Participating retailers currently include vendors of flowers, teddy bears and cupcakes.

One feature that did cause a stir, but mostly to raise hackles, was Facebook's Promoted Posts. This feature lets users promote content--for a price.

More widely welcomed were changes to Facebook's privacy controls. Facebook is usually dinged when it makes privacy changes, mostly because the company makes them so often and in such a confusing way, but these latest changes are designed to clarify Facebook features, mostly in context. According to Facebook, the changes are designed to bring controls in context where you share, to help you understand what appears where as you use Facebook, and to provide tools to help you act on content that you don't like. The new tools include a toolbar that enables users to change privacy and timeline controls from where they are working, more granular app permission controls, an updated activity log, and a tool that makes it easier for users to request that photos and other content they have been tagged in be removed.

Facebook even introduced a way for you to see your own year in review (pictured above).

What's coming in 2013? We can only speculate, but--note to Facebook--we really hope rumored video advertisements in News Feeds are not among changes slated for the new year.