I don't post a lot, but I do read a lot. What I have seen sometimes are new posters who post a lot and share a lot very quickly, then they disappear within a few weeks. In the meantime, people have equally shared their experience and invested a lot of time in reponding to the new poster. Next time round, another new poster who posts a lot and shares a lot very quickly and each time round, existing members are slower to respond.
Existing members are then waiting to see if the new poster is going to stick around, see if its worth engaging in a meaningful way. Particularly when the new member is posting a lot of personal info and asking others to exchange the same about them and/or asking questions that may take a lot of time to respond to.
Give it time, this may be an anonymous message board but some people still are still cautious and want to take time to get to know others in a basic way, see if they can relate to the person and their personal circumstances and/or their questions and if they do, then they engage in a more meaningful way.
A lot of people are short of time too, they like to come and go quickly and may respond to posts that do not require a lot of time.