What I notice with a few of my favourite models is that they come on, hang around for a couple of hours and shoot the breeze, get as many tips towards their goal as they can and just as they are about to do anything interesting, without fail they go into TruePrivate for up to an hour, then log off for the night (DaniSpice & NikkiPlease).
I have noticed this with a handful of really hot models and can only conclude that there is a very wealthy, cock blocking asshole (an old man with too much money, a kid from a rich family, or an idiot with a credit card) that wants these girls to himself, and can afford them. Ruins it for everyone else that doesn't have money to burn.
I've noticed that a lot of the girls have ridiculous token goals of 3-4 thousand in their topic for just going topless...Some get topless and then sit with just their face on the screen of have an overly large banner that obscures the view (RosieTyler). Even worse if she gets completely nude...Off screen, and she basically turns all the lights off so no one can see shit. But people enable it by pouring out the tokens, even though the girls show no appreciation and constantly bitch about people not tipping them.
If you check into a girl's room, see the token goal, you can pretty much time it to come back and see the show, or at least some nudity. It's actually kind of predictable.