This is according to ORC GamblerTrack, an annual study carried out by research consultancy ORC International.
It adds that all forms of traditional betting – telephone, shops, casinos and on-course betting – have seen a sharp decline in 2004, probably due to increased Internet access and the rise of online gambling.
However, online gambling remains small overall in comparison to traditional gambling methods, and still has a long way to go to seriously rival the popular National Lottery.
The study adds that online gambling companies are increasing their marketing investment in advertising, brand building and customer loyalty schemes, to attract higher income groups.
Despite a steady decline in gambling over recent years, 60 per cent of the UK population still participates in some form of gambling, contributing to an annual sales figure of £42billion.
