Couldn't have said it better Dave.
Dave spent ages sorting camp sites out and posting their details ages in advance but no-one chose to book.
So come a week from the actual show people moaned at us (why as we're organising a show and not a camping festival?) because they couldn't book any of the sites so we went out of our way to find a camp sites that will fit everyone in.
We found one but with limited facilities so we arranged to put in toilets which aren't cheap - look up the prices for yourself. It already has running water onsite and electrical hook up but now even that doesn't appear to be good enough, you want hot showers, a pub at the edge of the field and all within walking distance of the show?