Well done!
That's a good tip, particularly seeing as the lemmings in charge of the Post Office seem bent on self-destruction by greatly worsening the service (closing Post Offices, having fewer collections at odd times, later deliveries and a bizarre pricing new pricing policy) then raising the cost of postage, for this inferior service.
I'd have thought they were bound to drive even more business into the arms of the internet - on which, of course, this site also flourishes.