By Douglas A. McIntyre

One of the strengths of Facebook (FB), perhaps second to its 1 billion users, is the amount of time people spend on the social network. That length of time has been lauded as one of the reasons advertisers should use the site to market products and images.

But a new study from Pew Internet & American Life Project shows that people have begun to take very long breaks from their use of the world's largest social network. That, in turn, could hurt Facebook's appeal to marketers and erode its sales and precious revenue growth.

Pew reports:

61% of current Facebook users say that at one time or another in the past they have voluntarily taken a break from using Facebook for a period of several weeks or more.

20% of the online adults who do not currently use Facebook say they once used the site but no longer do so.

8% of online adults who do not currently use Facebook are interested in becoming Facebook users in the future.

Pew points out that 67% of American adults use Facebook, which makes the problem all the more extreme.

The reasons many people have begun to use Facebook less are all very bad for the company. Pew points out:

The largest group (21%) said that their "Facebook vacation" was a result of being too busy with other demands or not having time to spend on the site. Others pointed toward a general lack of interest in the site itself (10% mentioned this in one way or another), an absence of compelling content (10%), excessive gossip or "drama" from their friends (9%), or concerns that they were spending too much time on the site and needed to take a break (8%).

The worst of these is "an absence of compelling content." Facebook has never been able to solve the puzzle of how to get more outside content into the experience of its users. That leaves these people with little more than their relationships with friends. Even in the real world, friends become tedious from time to time.

The other problem Facebook clearly faces is that of Internet clutter. Most people are willing to spend only so much time online. They have commutes to make, food to prepare, sleep to get, and spouses, children and friends to deal with in the real world. Facebook competes for online time with a galaxy of news and information, entertainment, e-commerce and other social communications destinations, such as Twitter. The decision about how people use this Internet time has begun to move against Facebook, if the Pew survey is even close to being accurate.

Facebook's appeal is hardly over, but it may be in a period of erosion that it cannot realistically prevent.

Pew methodology: The PSRAI December 2012 Omnibus Week 2 obtained telephone interviews with a nationally representative sample of 1,006 adults living in the continental United States.

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