On 2009-10-09, Dave Liquorice  wrote:
> I can cope with the *cost* of a "unit" varying by time of day. For
> example with Economy 7 electricity you pay, say, 15p/unit peak rate
> and 5p/unit off peak. The electricity unit being a fixed amount of
> energy that is easy to measure, like the amount of download that has
> occurred in a given time period (peak/offpeak). This would translate
> on a BT 20CN line to a charge of £2.55/GB peak rate and £0.0225/GB
> off peak. On a BT 21CN line £1.70/GB peak rate and £0.0170/GB off
> peak. 
>
> In my view this is far, far, easier to understand. Thus you get a
> download "allowance" as part of your chosen tariff to spend as you
> will. This would be £7.65 on a BT 20CN line.

I think this sort of approach is probably easier to explain.

-- 
Andrew McDonald
Contact details: admcd.tel
http://www.mcdonald.org.uk/andrew/