As another example, advance-fare tickets from Aberdeen to or from Glasgow and Edinburgh can be purchased for as little as £5 while a walk-on ticket can be as much as £90. There are 16 services a day meaning it is £10 cheaper for a firm to buy an advance-purchase ticket, with an assigned seat, on every service than to buy a single walk-on service at the point it is required. This tactic is often employed by firms in the oil and gas industry and subsequently trains to/from Aberdeen often have many assigned seats which are not claimed initially, resulting in standing passengers occupying them as soon as the train leaves and it is established they are in fact empty.[citation needed]