• by Mark Walsh  @markfwal, September 30, 2010

The "Like" button and other social plugins that Facebook introduced as part of its Open Graph initiative this spring have spread across the Web, with some 2 million sites now using the tools. But who's actually clicking on the Like buttons and what value the plugins bring to third-party sites are questions that publishers and advertisers are still trying to answer.

To provide more insight, Facebook this week released new data suggesting that "Likers" tend to be more "engaged, active and connected than the average Facebook user," according to a post on the Facebook+Media blog. Specifically, people who click the Like button have 2.4 times the amount of friends than the typical Facebook user and click 5.3 times more links on Facebook to external sites than average.

So those clicking on links posted in the news feed, on friends' Wall pages, or branded Facebook pages are themselves more apt to click Like buttons and share back to Facebook in a viral loop.

In terms of demographics, the typical person who clicks the Like button on a news site is 34, while the median age of a newspaper subscriber is about 54, according to Newspaper Association of America data cited by Facebook. Then again, the average age of all Facebook users is well under 54.

When a Facebook members clicks a Like button on a third-party site, it sends a message to their friends with a link back to the site, adds the article to the reader's own profile, and makes the article available through a search on Facebook. The company suggests that publishers optimize the Like button. By showing friends' faces and placing them near "engaging" content without causing visual clutter, Facebook says click-through rates improve by three to five times.

By adding the Activity Feed plugin, showing what friends are doing on a site, publishers can generate four times more page views than the average media site, according to Facebook. It also says that Facebook brand pages can boost in-page interaction by 1.3 to 3 times by publishing compelling links or status updates ("things that are emotional, provocative, related to sporting events or even simple questions") to Likers, or fans.

Offering further evidence of the impact that social plugins can make, Facebook highlighted traffic gains for various sites after adding the Like button and other ones. ABC News, for instance, had a 190% gain, Gawker, 200%, and the Sporting News, 500%.

Some publishers with plugins also report that people are also sticking around longer and increasing on-site activity. NHL.com, for instance, reports that visitors are reading 92% more articles, spending 85% more time on-site, and viewing 86% more videos.

Facebook also recently launched a new metrics to help advertisers measure the social context of ads by tracking the proportion that include endorsements from friends. That means telling advertisers what percentage of their ads people Liked or used to interact with a Facebook Page, event or application.