[chc]

Not really. Most movies and sports aren't carefully crafted to induce psychological addiction like many Zynga games are. Zynga will actually make games less fun and less relaxing if there's some set of people who will be driven to play more (even if they don't seem to be enjoying it much) because of the changes.

[jiggy2011]

Is Zynga different in this regard? They design their product so that people want to keep playing it , in the same way that a TV serial will end an episode on a cliffhanger in order to get you to watch the next one. Sports also encourage you to emotionally invest yourself in a particular team and create long term stories (leagues etc) so that you will continue spending money.