"There are a number of reasons why I prefer Foursquare. One is that the Farmville compulsion loop is based on an 'appointment gaming' mechanism. Players must come back to the game at a certain time in order to harvest their crops (and get the reward) before the crops wither and die. This is known as a hard penalty. It seems so clear that a game designed to mimic my real-world life of appointments would seem like a chore. Working full-time and raising two small children with my even busier husband, I really don't need more appointments in my day. I don't want to log in and see that my raspberries have withered and died because I forgot to harvest them.
"The gaming mechanism in Foursquare is based on rewards, not penalties, and there is no appointment mechanism. I can check in as much or as little as I like. I was delighted when I got my Adventurer Badge. When I was mayor of my local café, I felt like I had finally arrived. (Mayors often receive special deals or discounts.) It's true there are some penalties. If I don't check in enough, I might lose my title of mayor–but it felt different then being greeted with a bunch of dead plants."
-Hot Studio Senior User Experience Architect Marsha Platt lays out why free-roaming gaming beats appointment gaming any day.