The pair claim the site, the first title from their newly formed online media company Grand Parade, is the first "to make sense of Britain's bet-on-anything culture".
The site offers entertainment as well as advice and is intended to drive traffic to gambling companies advertising on it. Sections launched so far include betting, videos and celebrity sports gossip.
Until last year, Clerkson and Needham were working for Dennis Publishing in New York, Clerkson as editorial director of Dennis US across Maxim, Blender, Stuff and The Week, and Needham as editor-in-chief of Maxim.
Needham was the launch editor of the US version of FHM, while Clerkson has spent the past 15 years at Dennis. Clerkson is now managing director of Grand Parade, while Needham has become editorial director.
The National Audit Office estimated the UK gambling industry's value at £53bn in 2005, a sum the pair are keen to get a cut of.
"There are a lot of gambling sites around, but few have any media around them," said Needham. "We're entering a subject area, a market that is under-served. The idea is to promote gambling as a lifestyle choice and get away from the murky, shameful image from which it has sometimes suffered."
Needham said he is confident of supplementing revenue from gambling advertisers with income from lifestyle brands and the company had some ideas for new sites.
"We're never going to get advertisers like Gucci or Prada," he said. "But we feel that, through our experience, we can put multinational brands in front of a large audience of young men.
"We're thinking about advertising on sports sites as well as coming up with imaginative viral campaigns to promote the site."
Needham cited financial constraints as the main reason for Grand Parade turning to digital rather than print as its main pursuit.
"Monthlies are struggling and weeklies take too much money to maintain," he said.