I don't think posts per day means anything because I post 30-50 a day yet im still at 1.6 per day.
the average post counter is really funky tbh
It measures your post count over the entire time you've been a member.
If I wanted a 40 a day rate on my profile by next week (say the 12th), then I would need to post an additional 94526 times in the next 7 days.
It's much easier to have a post rate in the double digits on a younger account, unless you do consistently post at a high rate every single day. If you start to take any sort of hiatus from posting, like a week off, or you lower the amount you post for some time, then your rate drops significantly.
Anyway, my point was less going by the rate count on the profile, and more just the act of maintaing 40-50 posts a day at any time, seems like a challenging feat. I've either got other stuff going on, or there's simply not that much stuff to interest me to post on it all here.