Quality not quantity etc etc. Though I do remember what it was like to be new to forums when I was a kid and think that postcount is basically your "awesomeness meter"; I once ragequit a place after I accumulated nearly a thousand posts only for them to be erased in some freak glitch. Everyone goes through this phase, and it can actually have a positive result as becoming a habitual poster eventually forges relationships with other members that naturally force you to make better posts out of pure conversationalism. If you're a frivolous borderline spam poster, you'll eventually realize that you're not getting recognition in spite of your 99999999 post count.
I guess I cared about post count when I was newer at PC, but it stopped mattering after a few thousand posts, and I don't really believe that I ever actually posted for the sake of increasing my post count. It was just sometimes nice to see that I was making progress as a member of the community, as while your friendships are the ultimate indicator of your acceptance, post count is at least indicative of your activity level. I certainly don't think that my post count is doing me any particular favors now, other than maybe have people wonder why my count is so astronomically high when they don't recognize me and give my profile a glance (I do enjoy the occasional VM, hint hint!)
I wouldn't doubt that in my days of obsessive posting I may have hit 100 posts in a day. Back in the
wonderfully,
chaotically active days of the DCC it wasn't unusual for several members to come close to or exceed 1k posts in a single DCC, and I averaged anywhere between 500 and 1k posts per DCC in addition to my activity elsewhere. When Member Fanclubs existed they didn't add to postcount but were like mini-DCCs unto themselves, so between all of that, the secret mod lair, and places I used to haunt like the Pokemon areas, I'm pretty sure I hit 100 posts in a day easily on several occasions.