In my whole life I have never filled in any of these surveys....anyhoo, EDI and GLA have rather different passenger profiles. There was a piece on travellers a few years back that showed PIK and MME right at the bottom of the pile.
EDI cannot support a single Toronto flight whereas GLA has a multiple weekly Air Transat Canadian services.
GLA can't support Air France, Iberia or Lufthansa whereas EDI has Air France, Lufthansa and connections to other major European capitals.
GLA has muliple based charter fleets from Thomson, Thomas Cook and others whereas EDI has very little presence in that market.