A container deposit system works by refunding event attendees an amount (say 10p or 20c) each time they bring a bottle back for recycling.
Event attendees pay a 'deposit' upon purchase of their beverage, and when they return it they have it refunded.
This system significantly increases the amount of materials captured for recycling at some events. At Reading Festival in the UK, this system was implemented through the bars in the entertainment arena. A 92% return rate was achieved, where previously the majority of containers were thrown on the ground.