I see people who've been here for the same time I've been with over 1500 posts, and people who joined three years ago with under 200, it seems to fluctuate widely. I lurked for ages, and looked over one friend's shoulder as they posted a lot. Many of their posts were basically mine, seeing as I liked to take over a lot.
I'm on maybe... 12 hours a week? Sometimes more, but generally less because friends, (chasing) girls, XBOX, school, university, exams etc. But some weeks I have nothing due, a bug's been around and everyone's bedridden and I only have a couple of lessons a week, and I just sit on the computer stewing in this perpetual swirling torrent of nerdstuffs that is www.gamesas.com