Yeah... But buying Rat Trap Trucks or Bloodmobiles or Cobblestone walls (or whatever) eats up your cash supply. It works for a quick "I need a few donuts right now!" situation, but then you're broke. KEM farming gives you a steady donut income. Do it right and you have donuts and cash left over for buying land, more buildings and decorations - or the occasional Rat Trap Truck spree.
About The Simpsons Tapped Out General Discussion
Talk about your The Simpsons: Tapped Out experience with other TSTO players.