A/B Test: Most Popular Referred from Facebook

This is a test to find out if visitors referred from Facebook are more or less likely to click through when shown the most popular links followed by other visitors referred from Facebook.

The test has two variants: the *control* group gets the normal 'Most Popular' list populated by the Content API; and the *facebook* group gets an alternative Facebook list populated by Ophan's API.  This test is only available for visitors referred directly from Facebook.