I think it will be OK in the end... the only concern of course is that we have a lot of visitors in London. Business trips, day trippers, tourists, etc surely make up a huge chunk of the "population" at any one time, so I think it needs to be a lot easier to buy the cards in the first place. Things like: - Signage in central London bus stops, in multiple languages, telling customers where they can buy cards nearby - Oyster card vending machines at every station (both tube and national rail) selling pre-loaded cards