The Huffington Post applies A/B testing to some of its headlines. Readers are randomly shown one of two headlines for the same story. After five minutes, which is enough time for such a high-traffic site, the version with the most clicks becomes the wood that everyone sees.
..Think of it as a more rigorous version of magazines adjusting their covers based on newsstand sales.

Paul Berry, chief technology officer at The Huffington Post… said the system was created inhouse, but he wouldn’t disclose much else about how or how often it’s done. He did say Huffington Post editors have found that placing the author’s name above a headline almost always leads to more clicks than omitting it.

Though it’s unrelated to this A/B testing, The Huffington Post’s new social media editor, Josh Young, has also been soliciting better headlines from readers on Twitter. That’s not as awesomely scientific, but it’s a pretty good use of the crowd.