Snip from the article:
(1) Farmville is defined by obligation, routine, and responsibility;
(2) Farmville encroaches and depends upon real life, and is never entirely separate from it;
(3) Farmville is always certain in outcome, and involves neither chance nor skill;
(4) Farmville is a productive activity, in that it adds to the social capital upon which Facebook and Zynga depend for their wealth;
(5) Farmville is governed not by rules, but by habits, and simple cause-and-effect;
(6) Farmville is not make-believe, in that it requires neither immersion nor suspension of disbelief.