The addiction to mafiareturns is something that I have seen people fight with many times. In fact, I have fought it once or twice. The battle is not something that can be won. This is shown in the fact that people who end up banned from mafiareturns find ways around their ban.
As for my addiction, it can't really be the people, because until recently I didn't really talk to anyone. However, having been here for roughly 4 years now, I would say it is the way the game is set up. It's not like any other game out there and never will be.