I joined AFF in 2007, right after my first marriage ended. To be honest, I was naive enough coming out of that marriage that I thought the "Friend" part of the site name was literal.
I figured it out pretty fast, but stuck around because one of the biggest issues in that marriage was the lack of any sexual enjoyment or (on my then-husband's part) comprehension of how anything worked.
I met Hubby on AFF. After we got together, he pretty much stopped visiting the site; I just hung around the chat room for my geographic area, because I had friends there. When he and I opened our marriage, we started being more active on the site, and that's how I met Guy. It's also how I met Best Friend.
Fast-forwarding, I started the profile on OKC this spring, after I saw the site mentioned on these forums, because AFF didn't seem especially poly-friendly, and I was getting a bunch of jackasses saying things like "Ooh, your husband doesn't satisfy you, let me show you how a real man does it" or "You're cheating on your husband, you must be a horny slut."
But I didn't have any better luck on OKC...and then S2 started messaging me on AFF, and so far that's going pretty darn well. I realized this morning that today is 5 weeks since S2 and I had our first date, and so far we're still chatting regularly and enjoy spending time together, so AFF ended up being the right choice for me once again. LOL