That was my first thought too, seems like the simpler solution and the way I've built multi-site apps in the past. It sounds like they are still using a differ

That was my first thought too, seems like the simpler solution and the way I've built multi-site apps in the past. It sounds like they are still using a different database per site, as opposed to one database and scoping data by an account_id. I wonder what the performance gain is over the complexity it adds. I remember this is the same way that FogBugz was setup too and they ran into issue when they had so many small databases instead of one large one.