I think this is kosher - both ways, too. In the 70s my folks worked a deal out with their landlord. The building had turned into a giant shooting gallery, so they patrolled the vacant apartments and chased junkies out or called the cops when they wouldn't leave.

In return, they were able to connect two separate rent controled apartments and create one rent stabilized apartment. I live in that apartment today and the (new) landlord has a similar relationship with me, only instead of chasing out junkies I help NYU students function like adults. My super is very happy he doesn't have to drive in from Queens because someone does not know how to turn their radiator off.

How times change.