In my experience its unusual. Lots of people going on holiday at this time of year, and would appreciate a bit of notice as to whether they need to be at a computer on Tuesday or not.
Bound to happen. People will see it as a modest premium to keep place in line for Arsenal and West Ham by paying for Lesta/Watford. Others will buy to get up the ladder.
Club will no doubt reiterate their spot checking outside stadium policy but that's not going to work.
They might have to...