Video games have quietly overtaken older entertainment forms such as films and popular music. According to the latest figures from Elspa, the industry body, game software sales in Britain for the first half of 2007 were £519 million, 17 per cent more than in the corresponding period of 2006. A leading game, such as the recent Halo 3, can cost $70 million (£34 million) to develop and a mobile game a fraction of that. The possible rewards are vast. Halo 3 outstripped many blockbuster films in the week that it went on the market, generating sales of $300 million.