because line rental/call charges are higher on a mobile,
thus covering the cost of providing a Caller ID service

/guess but seems plausible
( Fergburger, Mon 11 Jul 2005, 15:27, archived)

That's the thing I can't get my head around.
How much can it possibly cost the network to forward an 11 digit number whilst making the connection? I'd imagine as good as nothing.
(Nothing to see, Mon 11 Jul 2005, 15:30, archived)