It is conservatively estimated revenue based in part on minimum...

It is conservatively estimated revenue based in part on minimum comitments and possible customer takeup.  It may end up being different - or it may not.  Such is the nature of forecasts.  As Paul noted on the call, there are the usual contract terms at play as well - Spark can terminate for cause etc. (Obvisouly Norwood does not expect this)

The company has taken a conservative estimate on reasonable grounds of what the propsective future revenue will be.  They are under an obligation to the market to keep investors informed if the estimate looks like being wrong, and of course there are quarterly cash flow reports every 3 months.