Ann: Corporate Update and Quarterly Reporting, page-124

Currently they are charging a flat rate per minute .
Cost to provide minutes will vary greatly depending on location and destination of call.

Whilst annualised revenue can be extrapolated as minutes billed x price. It is currently much more difficult to extrapolate the cost and therefore profit as this will vary greatly with call destination.
I'm assuming that the average margin is high.....
But will be much more comfortable with NOR margins and variable costs when World Credit is giving management control of this crucial area.