I saw this "Association Bonus" on a relatively new user's profile on the reputation tab, not sure if it is for being on 4 stackexchange sites:
I am prety new too, just wondering what this is.
The association bonus is a bonus given when a user has an account on a Stack Exchange site with a reputation that is higher than 199; then bonus is given for every account the user has, even the ones created in the future.
The bonus is given the first time a user's reputation reaches 200. If the user's reputation is at least 200 in more than one site, the association bonus is still 100.