^ Now that is something I've wondered about myself. As you said, are they introduced as a group of idols or do they specifically mention that they are a collection of gravure/AV idols? I've no sense on how popular the group is in Japan and I'm certainly unaware of any appearances on any other show other than their own. But then I have no access to these shows so I honestly couldn't tell you. I have seen Sola on one once before way back when she tried out a solo career so I guess it's possible. It seems to me like the core fanbase probably does consist of those who buy these girl's IV's/AV's and anything they do, like single's/PV's/appearances on the show is catered to them.
The other thing I wonder about is how do the girls themselves feel about it? I'm sure it's a welcome relief for them, something to have a laugh with friend's they've made in the industry, but are there a few that don't want to be there? A few who feel like they shouldn't be there or any who get jealous at how much airtime is given to the more popular ones like Acky or Rio?
I don't like to think about it for too long though! In my head, they're happy with what they do, they all love each other and then they meet up afterwards for an orgy with me right in the middle......wait, what?