Joining a CFA local society?

Could someone shed some light on the need for joining a local society, and what exactly the difference between an affiliate and a regular member? Reading here and there didn’t get me very far. Since I am a candidate with CFAI, do I join a local society as regular or affiliate? Do I have a choice? Do I have to do this anyway?

So I went to the Stamford CFA Society meeting once. They had a cheap buffet dinner at a local restaurant and then a guy from Pollack, Richardson, Auerbach (a boiler room equity shop) gave a talk about the conspiracy by big oil to take down Bill Clinton, including a detailed description of the evidence that Monica Lewinsky was an oil company mole sent to seduce Clinton and publicly humiliate him. I’d rather watch Law and Order re-runs.

The DC CFA society seems to have some really good discussion events, networking receptions, career days, etc. I haven’t joined yet, but plan to soon.

I believe the difference between an affiliate member and a reguarl member is passage of the exam. If you pass LI, you can apply to become a regular member.