Queue to automatically join full channel?

Is there a way to add yourself to some sort of queue to automatically join a cam channel as soon as someone leaves? Seems like there is because the open slots are filling instantaneously every time. I don't see how that could happen unless either

(1) there's an automatic queue

(2) there's a huge number of people trying to get in so it's an odds thing, which seems unlikely since there's another channel for the identical topic but it has hardly any people in it and often none at all (or maybe people just don't want to join it)

or

(3) every time there's at least one person sitting there for 15-odd minutes clicking nonstop on Join (also possible but seems unlikely?)