It appears I joined exactly 2 years ago, yay me!
I started lurking a little earlier than that when I decided I was going to take the plunge and I started doing research. The old reviews (miss those) helped me decide where and with whom I would try to party with first, Coco at Inez's in Elko. I joined immediately after that to post my review and I have stuck around since. While I enjoy reading the "banter", I think I enjoy chatting/PM'ing with people even more.
Like sixt9er, it is now habit. I pretty much automatically check SIN, just like I check Facebook, some other favorites sites.