The term was indeed a direct analogy with ‘post-industrial’. A post-industrial society is not a non-industrial one. It continues to make and to use the products of industry, but the energy and innovative drive of the system have gone elsewhere. The same applies in a more complex way to post-modern, which is not the same as anti-modern or of course pre-modern. It implies a culture that uses the achievements of modernism but departs from them in its search for new possibilities. A post-democratic society therefore is one that continues to have and to use all the institutions of democracy, but in which they increasingly become a formal shell. The energy and innovative drive pass away from the democratic arena and into small circles of a politico-economic elite. I did not say that we were now living in a post-democratic society, but that we were moving towards such a condition.
Interesting post by Mark Carrigan 
that mirrors a couple of recent conversations I've had on similar topics e.g. the illusion of democratic functions when money buys the ability to set the agenda.
This quote from Colin Crouch sums up the idea nicely:
I read this after reading McKenzie Wark's The Weird Global Media Event - and started to think if they are a symptom of post-democracy. Is this what a social response looks like? This idea of narrative is interesting :
That it is an event demands a suspension of open-ended thought. The event invokes the master-scripts of ideology, which the event will be made to fit. That which at first exceeds everyday little stories is recaptured by grand narrative.
Who sets the grand narrative? Where does it comes from? Is it for and by the people? Is the narrative democratic or has it replaced it?