Among the things the Huffington Post did that helped make it a social-news behemoth was to integrate Facebook’s open platform (then called Facebook Connect) into the site almost as soon as it was launched — something that immediately allowed readers to see what articles their friends had read, shared and commented on. That drove millions of readers to the site, and also boosted the number of comments by over 50 percent. And the site has also integrated virtually every other sharing tool known to man to make it easy for readers to share, and even come up with some of its own.

via How the Huffington Post became a new-media behemoth — Tech News and Analysis.