It's difficult for me to say exactly. Strictly speaking, I've been on the site for 2 years, but there was a loooooooong gap between my last failed RP and me returning this year. If we added all my time actually spent here I guess it would be maybe 3 weeks, tops.
Yet oddly I seldom leave Free. Not because I dislike lengthy posts, I just prefer being free from all restrictions, plus it means I don't need to strain myself to make an unneccesarily detailed post. I am in my first one-on-one, and I have to say it is the most enjoyable RP type I've ever had.