I think some of you miss the point. If you have paid 1p for your seat, if you then want not to travel, it must be fair to charge you for the admin.
If you have paid £200 for your seat and want to cancel, I expect you would then find you may well get a fair proportion of it back.
Having said all of this. Most people these days tend to buy the cheapest ticket, regarles of who it is with, or even what mode of transport. These tickets are normaly non cancelable and non transferable.