Hostin' and runnin' a role-play takes a lot of hard work and dedication. It doesn't just happen on a whim and everythin' goes as planned with highly active members, new recruits seekin' to join on a daily basis, everyone online role-playin' and behavin' like they should 24/7, etc. It actually takes weeks, months, for a role-play to even begin to spread its wings. By then it may wither out if unlucky. Nowadays, in my opinion, it's very scarce to find a role-play that still soars high. Most are still in that premature stage so to speak. Those that I have seen flappin' their wings have been around for years such as The Ebon Circle, Untamed Rebellion, The Benevolent Wolf Pack, Red Reverence, etc and even then they have their ups and downs but they also have a lot of history and strong ties.
It also, again, takes a gut load of patience, dedication, and loyalty in order to even be a part of a role-play alongside, much more if ye' decide to host one. I wouldn't get down about only a few members at a time joinin' yer organization (better than no one at all, right?) or yer role-play partner bailin' the next day. In order to find a keeper, ye' sometimes have to pick out the loose ends. This goes for those establishments ye' join as well. Give the group a few days and if ye're positively sure they've gone inactive, seek out a new one or kick those that have gone rogue and begin anew. It would help to enthrall yer fellow members via involvin' them in idle conversation or incorporatin' a plot ye' all can role-play by. Enforce a schedule if ye' must such as times when the group will be role-playin', when they'll be advertisin', etc. It may help.