How many weeks of not playing do you give a neighbor the boot?

I also think that the leader board is a good help. If they have 0 currency of whatever the event is, I go and check them after a week or so. Usually I give them 1 week after that, if there is no progress.

But sometimes you can "use" their towns for a long time anyway, like dumping garbage os so. Then when nothing left to tap, and I check up on them it says "last played 6 weeks ago". Oh... well, off with their heads...