On Tuesday I bought, for the first time in ages, a peak one-day all
zones travelcard, at the quite new (less than a year old) ticket
machine outside Crayford mainline station in Zone 6. It cost £12.40,
which is what I expected.

On Thursday I did exactly the same thing in exactly the same place at
about the same time, but there were two differences.

1: The machine rejected my debit card before I'd even had a chance to
enter a PIN, but the card processing on this new machine seems hopeless
anyway and is out of order in some way almost as often as it works, so
that didn't surprise me.

2: More interestingly, the travelcard only cost £12.00. Why the 40p
reduction? Anyone know? I was worried that I'd picked a wrong option or
something but the ticket happily worked on the train, the DLR (my first
DLR ticket inspection!) and the tube all day so it seemed to be what
I'd asked for.

A glitch in the machine or a proper reduction, perhaps by way of
compensation for the fact that I currently have to pay 50p over the
odds for a day out in London, until South Eastern implement Oyster
Pre-Pay?

Paul