I think that desperation for ppl to post is not the best thing.
I really see the site die out over time.
PPl subscribe and are friends on youtube and facebook, and if theres anything theyll just probably get in touch by chatting there.
The same by watching videos.
Also i think that most ppl are lazy or just dont have the time or effort to hang around here as much as before.
Ppl grow up and got things to do and hanging around beyond is probably not the main activety of the day.
The site doesnt really offer anything youtube or facebook can provide, so my tip for getting more ppl to post regulary is to create that xtra something that would make ppl choose this site infront of other sites.... Dunno how you gonna do it though, but it will be a though job.