n additional 3.2 million people visited online gambling sites last year, a 40% increase over the previous year, compared to the extra 2.2 million who accessed social networking sites such as Facebook.
UK lottery giant Camelot also topped Nielsen’s chart of the fastest-growing companies online, increasing unique visitors by 4.4m to 9.4m between July 2009 and July 2010, representing an 88% year-on-year increase. Nielsen credited its display ad campaign for National Lottery EuroMillions.
PartyGaming came in 8th on the list, increasing its customer base for PartyPoker and PartyCasino by 1.2m, or 186%, to 1.9m. Partypoker.com yielded an extra 870,000 visitors last year, increasing its audience by 174%.
Nielsen said nearly half of all online gamblers earned more than £30,000 per annum from their day jobs. While middle-aged men drove the spike in numbers, according to Nielsen, women represented 46% of online gamblers.
Neil Beston of Nielsen said: "While the phenomenal growth in gambling sites over the last two years has been driven by men and women of all ages, it appears to be powered particularly by middle-aged men, the well-educated and high-earning households."