The world's biggest ever lottery, with a top prize of $1billion, has been launched on the Internet.

Not that there was any shortage, already, of ways to make your fortune or lose it when you are online.

The lottery, which got underway on October 1 and ends on December 26 this year, is hosted by the American website Grab.com.

American billionaire investor Warren Buffett has stepped up to insure the lottery, although experts say the chances of his company having to pay out are slim.

Buffett's National Indemnity, part of his Berkshire Hathaway insurance and investment group, has written a policy for Grab.com to cover the possibility of a $1 billion payout.

For a premium of "several million dollars," according to Grab.com co-founder and president Andrew Warner, Buffet's firm will pay out the prize money if any players manage to match seven numbers from 1 to 77, which are to be randomly selected by Grab.com on December 29.

On closer inspection, however, the bet is not too risky for Buffett, an avid bridge player, as the odds of anybody matching seven numbers out of 77 is about 2.4 billion to one.

Better stick with sports betting, you might think and you wouldn't be alone if you did.

The recent explosion in that market has led to newly floated betinternet.com posting a sevenfold rise in turnover.

In the year to May 31, they raked in £11.7million in wagers from punters, either by phone or through the Isle of Man-based website.

The site expanded rapidly during the year, with punters in 85 countries now being able to have a punt but not UK residents, who are excluded because of the tax implications of the website being based on the Isle of Man.

However, the company is looking at the possibility of bringing the website's services to domestic gamblers.

Meanwhile, company chairman Vincent Caldwell said plans to diversify away from its horseracing roots had been successful.

A wide range of sports, from golf and Gaelic football to rugby and basketball are featured, and booming in popularity.

From contributing just 10 per cent of bets in the previous year, non-racing bets now bring in 60 per cent of betinternet.com's revenue, largely boosted by betting on football.

Mr Caldwell said he had been pleased to see turnover increasing to £11.7 million in his company's first set of results since floating on the London Stock Exchange in May.

This compared with £1.54 million for the 17 months to May 31 last year. But heavy investment in the technological infrastructure and on marketing meant the company reported increased pre-tax losses to £1.04 million, against £304,000 last time round.

The massively increased turnover since the end of May was likely to mean the company would turn in a profit soon, said Mr Caldwell.

In other words, the company fully expect to make a fortune.