San Francisco - If anyone still questioned the power of the internet to play a key role in the general elections, the recent fundraising figures touted by Barack Obama should put all doubts to rest.

The Democratic presidential nominee raised a staggering 150 million dollars in September - most of which came from small donors who gave less than 100 dollars each through Obama's website.

Thanks largely to the unprecedented use of the internet, Obama's campaign attracted 632,000 new donors in September. By some estimates Obama's internet activities have now raised more than 1 billion dollars since he started campaigning two years ago. That's more than 10 times as much as John Kerry raised over the internet just four years ago.

That staggering achievement may not be the most decisive impact of the internet on this year's election. According to political analysts, it was the huge flow of volunteers to Obama's website when he first started considering an election run that convinced him that he had a chance to defeat Senator Hillary Clinton, then the overwhelming favourite for the centre-left nomination.

As Obama's online network multiplied, it gave him a decisive edge in the primary battles against Clinton, allowing him to deploy thousands of volunteers on short notice and with devastating effect, said Joe Trippi, a Democratic campaign advisor and online political guru.

"In 1992, it was the economy, stupid," Trippi told the MIT Technology Review. "This year, it was the network, stupid!"

If Trippi is right, November 4 should be a cake walk for Obama.

According to the Pew Research Centre, Obama's campaign website has consistently attracted about three times the traffic of the website of his general election opponent, Republican Senator John McCain.

On Facebook, Obama has 2.2 million "friends" compared to 745,000 for McCain. On MySpace, Obama has 588,000 friends compared to McCain's 188,000.

Obama's web team, which includes Chris Hughes, the 24-year-old cofounder of Facebook, has also done a thorough job of integrating online activities with real world actions.

They reach out to supporters through a multitude of platforms - from emails to SMS messages, and from viral videos to posts on the new medium of the moment, the Twitter cellphone network. Obama has even taken out ads embedded in video games, urging voters to head early for the polls.

In contrast, McCain's use of the net seems like an afterthought. His online game is called Pork Invaders - which is styled on the late-1970s game Space Invaders with a twist against government waste, so-called pork. As such, it seems designed not to appeal to the vital young voting demographic, but perhaps to their parents.

McCain has used internet advertising to his advantage.

He trails Obama badly in the money he can spend on advertising. Putting ads up on the net helps him bridge that gap.

"Thanks to YouTube - and blogging and instant fact-checking and viral emails - it is getting harder and harder to get away with repeating brazen lies without paying a price, or to run under-the- radar smear campaigns without being exposed," wrote Arianna Huffington, the doyen of left-wing bloggers.

"The internet may make it easier to disseminate character smears, but it also makes it much less likely that these smears will stick."