I thought it would be cool to have something like this with apartments. A company has apartments all over a city/state/country. A renter can move to any of the properties without breaking the lease or paying crazy fees. (Dependant on openings of course)

This way the apartment company can keep good tenants and the tenants can move around as needed with less burden.

I don't belive this will work in the realy world because of greed and whatnot but it's a nice idea.