[@BrokenPromise] I feel like that is a [i]really[/i] apt description and cause analysis but I think it's also missing some more intricate points that as a GM are hard to work with. The starting point is doing what you did aka figure out who is doing what, and where, and how and so forth. 

Analysing what is happening is a lot easier than actually talking to people and telling them that they need to do x or y in order to advance. And then there are the people who say 'I'll post!' 20x and then never post over the duration of a month. (BONUS POINTS: they're also 'that guy' who posts 2 weeks after the RP has officially died and then goes 'what the fuck!?!? Where is everyone!!!' in the OOC.) 

So what that means to me is that a lot of the times, analysing it is like you said, only the first step.. the second and harder step is getting people to change their behaviour in order to advance the RP. Something I find really hard because, if I have to motivate people to post... then they're probably not _that_ interested in the RP to begin with. Is it worth continuing with people who don't care?