That's great news for the model that you follow, I hope she continues to build her room and be successful!
I've been a fan club member for one particular model for years, she tells me only a couple of others have ever signed up, and I'm the only one to keep renewing......
I would guess that those other users did it to take advantage of the PMs available to FC members, as she doesn't have any content available at all - so it's the only benefit apparent to users.
I keep FC membership because I think she's awesome and that's an easy way to show how much I appreciate her (in addition to lots of tips!), but I have never used FC membership to initiate a PM convo with her.
The absence of any other content is irrelevant to me, but I'm sure that if she did offer some, then she would generate more membership. So in the case of your fave model, having regular updates is likely going to help new signups.