[xsmasher]

Interesting. I've worked on two games that include a "clean up" mechanic - one where you tap buildings to collect taxes every few minutes, and another where trash collects on the map and you have to tap to clean it.

The users loved the tax mechanic and hated the trash mechanic, even if they earned the same amount of coins for the same clicks. One felt like getting a reward, while the other felt like doing drudgework.