Which PhysicsOverflow discussion pages have a submission rate of more then 8,000 per month?
PhysicsOverflow:  It allows users to ask, answer and comment on graduate-level physics questions, post and review manuscripts from ArXiv (which lists PhysicsOverflow discussion pages among its trackbacks) and other sources, and vote on both forms of content. ArXiv:  By 2014 the submission rate had grown to more than 8,000 per month.
ArXiv