I originally joined this site around four or five years ago, mostly lurked for maybe 6-12 months, before losing interest and deactivating the account. I honestly don't remember why I joined to begin with, but I probably stuck around for the porn links, back then. Not too long before that, I had an ex-girlfriend who made a huge deal out of my 'huge deal', so I guess it was on my mind at the time. And it is not usually socially acceptable to talk about having a big penis with people in one's real life -- it tends to be regarded as perverse, or bragging, or both -- so it's nice to be able to mention it somewhere with people who don't care, considering it is something that affects my sex life.
I suddenly thought about this site again one day, a couple of months ago, and rejoined on a whim while drunk and bored. I guess I have stuck around because of the few members whom I have gotten to know the person behind the screen name a little bit.