The next lesson to take from behaviorism is that consequences can relate results because they condition people. This was the loop that I talked about with operant conditioning. And to the extent that it works, it works based on people learning to associate certain results from what happens in a game or some other kind of system. So here's an example from Farmville, the spectacularly successful social Facebook game from Zynga. Farmville has this concept of crops withering. The game is about you creating your own farm. You grow different kinds of crops and build things up and so forth, but you have to water the crops periodically because if you don't, the crops look like these ones here. They wither, and each set of crops has a specific time limit when the crops, mature and they can be harvested. You want to harvest the crops because then you can use them for other things, but, at a certain point in time, if you don't harvest them and don't water them enough, they turn into these brown withered things that you see here. And what FarmVille was able to do based on this structure was create what's called an appointment mechanic. And the idea is that people know that they have to come back at a certain time interval to water their crops or to harvest them because if not, they're going to wither. And that creates this draw because people start to realize, well, I'd better check in every day or maybe every hour to make sure my crops aren't withering. To make sure that I kept things up to date, because if I don't, then I'm going to lose out. And this draw of having to constantly check in and tend to your virtual farm was part of what made Farmville so powerful and successful because it got people learning to just as a matter of habit regularly check back in. That's a very behavioral kind of approach which worked well for Farmville.