However, many people are unhappy about the growing influence of big business in education. Schools should encourage free-thinking - the opposite goal of advertising, which tries to influence our thoughts in a particular direction. They argue that vending machines promote unhealthy food and drink at a time when obesity in young people is a serious problem in Britain. When Cadbury's, who make chocolate in the UK, offered to supply free sports equipment to schools in return for vouchers, there was a big protest. It was pointed out that pupils would have to purchase 5,440 bars of chocolate in order to get a free volleyball set!