Via Nieman Labs:
Not sure if you want a straight, newsy headline or something with a little more pizzazz? Something keyword-dense and SEO friendly or something more feature-y? This plugin lets you write two headlines for each post and have them presented at random to readers. The plugin records how often each version of the headline has been clicked and, once it has enough data, swaps full-time to the most effective one.
If you’re in the kind of operation that has regular debates over headline strategy, here’s a great way to test it. (Although note that this is measuring clicks on articles within your site — it doesn’t tell you anything about the SEO effectiveness of a headline. You’d have to wait for Google data for that.)
We have lots of debates over the appropriate role of audience metrics in journalism. But personally, I’d rather have those debates armed with as much data as possible. If you want your site to be filled with puns and plays on words instead of SEO-friendly nouns, fine — but it’s worth knowing how much of a traffic impact that decision has when you make it.