For the love of god, add a priority system.

[Jojoya]

Can you point out a currently thriving sub based game that does it?

Considering WoW is the only other MMORPG that is technically sub-based (even if the B2P and F2P MMORPGs also offer a sub option they aren't sub-based), clearly the answer would be no.

But then no one could prove that it was housing that caused past games to fail, either.