• by Mark Walsh  @markfwal, February 3, 2014

A decade after Facebook’s launch, what’s the biggest reason people use the social network today? To share photos and video (47%) and the ability to share with many people at once (46%).
 
The Pew Research Center’s Internet & American Life Project study, released in connection with Facebook’s 10th anniversary this week.
 
The high level of interest around video-sharing is something Facebook wants to monetize more directly with the introduction of video advertising. The test of autoplay video ads announced in December could eventually lead to a more TV-like version of the social network, with “commercials” becoming a regular part of the news feed.
 
Among other top reasons people using Facebook were getting updates or comments from others and humorous content, both cited by 39% of survey participants. Other aspects of Facebook, such as keeping up with news, or getting support from people in one’s network, appealed to a more modest audience of users.
 
What annoys people about Facebook? Oversharing by friends and people posting someone else’s personal information (such as photos) without first asking permission. In that vein, the study found parents are especially protective of their children, with 57% of Facebook saying people posting pictures of their children (under 18) without asking permission is something they strongly dislike about using the social network.
 
The “fear of missing out” phenomenon doesn’t play a significant role in shaping attitudes toward the site. Just 5% of Facebook users say they strongly dislike that Facebook allows them to see others taking part in social activities that they themselves were not included in—and 84% of users say this aspect of Facebook life doesn’t bother them at all.
 
Half of all adult Facebook users have more than 200 friends in their network, while 39% have between 1 and 100, 23% have 101 to 250, 20% have 251 to 500, and 15% have more than 500. Younger people tend to have much larger friend networks. For example, 27% of 18-29 year-old users have more than 500 friends, while 72% of users age 65+ have 100 or fewer.
 
Pew recently released findings indicating teens aren’t abandoning Facebook, despite various surveys and anecdotal sources indicating the age group is shifting toward alternative social media and messaging platforms, such as Vine, Instagram and Snapchat. But many teens interviewed suggested growing disenchantment with Facebook because of an increasing adult presence, among other reasons.

The Pew study is based on phone interviews with a sample of 1,801 adults 18 and older and conducted from August 7 to September 16, 2012. (The survey has a margin of error of plus or minus 3.5%).