It took me a long time to figure out why tapping a building that leaves graffiti, what it does. I believe it lowers their percentage meter so they get less in game cash. If you ask me, it's a bunch of BS. When I'm looking for new friends, if someone says they'll dump me if I leave graffiti, I don't send them a request in the first place. I have several friends now, that tap off every building in their towns when they play, and only leave the graffiti buildings to be tapped. I look around to try not to, but I'm not spending 5 minutes looking for other buildings. I have 92 friends now, and can have a total f 101. Going through 101 or whatever takes well over an hour to do so, and I'm not that anxious to return within a 24 hour period hoping to find non graffiti buildings to tap.
