Hey, Farmville fans. When you log on and plant seeds, you're not actually enjoying a game. You're stuck in what's called the "Sunk Cost Fallacy".
What is the "Sunk Cost Fallacy"? The You Are Not So Smart blog explains:
The Misconception: You make rational decisions based on the future value of objects, investments and experiences.
The Truth: Your decisions are tainted by the emotional investments you accumulate, and the more you invest in something the harder it becomes to abandon it.
This is how, the theory argues, Farmville gets its hooks in players. Once you get a farm up and running, you have an emotional investment in it. So you return and tend to it constantly not because it is fun, but because you feel you have to. That if you don't, all the previous hard work, time and money you put into it will be wasted.
Even though you're putting in even more hard work, time and money to keep that feeling at bay.
It's some sick, evil genius at work, isn't it? Note: the same argument applies to dozens of other games. Animal Crossing, I'm looking at you.