@Llati thanks for commenting - you raise some excellent points.
I intentionally didn't provide too much detail re: the business model/network effects as I think that is coincidentally why data centres are still misunderstood by many. The 'tech speak' used regularly by some of the market (brokers etc) - and many businesses about their very industry - contributes to some of this lack of understanding, in addition to the fact that NextDC is obviously a fairly complex business. I am not suggesting NextDC do this, although they do get very 'fluffy' at times - but in fairness to them they work in a very technical subject-matter so it's hard to avoid. But my colloquial language was more an attempt to avoid some of that fluff that is pretty common in the tech sector.
@Alpha18 has nailed it - the network effects stem from interconnections. Guarav also did an interview on Equity Mates last year (I will try and find it) which provided a fascinating break down of some of the intricacies associated with that side of NextDC's business. I also found this document (opens a PDF) super useful re: the benefits of residing within a NextDc facility - which to me is a compelling example of why we might be seeing a powerful network effect in play.
@Alpha18 - the revenue break down is spot on mate, particularly the comparison with more advanced O/S competitors. I am really hoping that portion of NextDC's revenue increases steadily over the coming year or two.