Fan Club Membership is a location-based challenge in Mr. Torgue's Campaign of Carnage. To perform this challenge in Badass Crater of Badassitude, it is required to find the hut located along the outer rim of the crater. It is worth 4 Badass Rank.
The hut is found in the area northeast of the Catch-A-Ride station closest to the Fast Travel (in the southeastern part of the map). The path to the hut consists of a series of metal platforms, stairs, and a ladder leading upwards alongside the rocky crater rim.