IMO the discount for season ticket holder at another track is a no brained even if the discount was no more than a free programme it could be enough to get an extra spectator through the turnstiles. For example a Poole fan on holiday in the Lake District decides to pop along to see Workington he pays normal admission fee but as he has his S/T he gets a free programme a small price I would think for Promoters. You could even do it when the opposition are in town say a team has 100 S/T holders and instead of 10 turning up they all do that's got to be a decent earner.