The 2008 election was as equally determined by the popularity of traditional mainstream television clips broadcast on YouTube as it was by the work of influential professional journalists blogging for free on leading websites like HuffingtonPost. The truth is that old and new journalism have converged in America to form a hybrid media which has synthesized the new democratic interactivity of the Internet with the traditional curatorial habits of edited-from-above media.

On a financial level, of course, the internet really has changed everything about American politics. Certainly Obama couldn't have challenged Hillary Clinton or radically outspent John McCain without the estimated $500 million in small donations mostly raised on the Internet. Nor could his campaign have had its remarkable success without its efficacious use of the most up-to-date viral marketing tools of digital technology such as the microblogging service Twitter and the cell phone texting technology Obama used to broadcast his selection of Joe Biden as his Vice-Presidential pick. Indeed, the online development of the Obama brand itself is a casebook example of how the viral internet enables the guerilla marketing of sexy products such as handsome young Harvard educated politicians with messianic messages about redemption and change.

But then again, the 2008 election proves that popularity on the Internet doesn't guarantee success. The more than $20 million the libertarian Ron Paul raised on the internet is now forgotten. Internet evangelists also conveniently forget the other 50 per cent of Obama's money which was raised conventionally, by a wealthy, politically powerful elite calling other wealthy elites on the telephone or meeting them at their private clubs. What Obama's success proves is that having a strong Internet presence is only half the story; the other half is having the Chicago Senator's charisma, his political judgment, his speaking skills, his intellect, his personal network, his advisers. And, of course, what is also conveniently forgotten by the digital crowd is that while Obama himself is a always-on BlackBerry addict and a social-network fiend with hundreds of thousands of Facebook "friends", his key political relationships – with advisors David Axelrod and David Plouffe and with Joe Biden – were all forged in the classically analog environments of the US Senate or on the streets of Chicago rather than in the abstraction of cyberspace.

Yes, the blogosphere has been remarkably influential in shaping public opinion in America. But most of the new aristocracy of political bloggers – former New Republic editor Andrew Sullivan, for example, or best selling author or ex American Prospect journalist and Talking Points Memo founder Joshua Micah Marshall – are all highly innovative refugees from mainstream media who are culturally or intellectually indistinguishable from the newspaper journalists they are seeking to replace. Meanwhile, big media – New York Times, CNN and Wall Street Journal - has also "discovered" blogs and user-generated video content and the interactivity of their sites are increasingly indistinguishable from well financed, popular blogs like the Huffington Post.

Much has been made of the YouTube election – the idea that user-generated content on video social networks have come to replace television as the dominant medium for influencing voters. But what has also been forgotten is that user-generated videos on YouTube didn't determine Obama's victory. The historically memorable and most influential moments in the election – Hilary Clinton's tearful interview on the eve of the New Hampshire primary in January, Obama's speech in front of those mock classical pillars at the Denver Convention, Sarah Palin’s shockingly revealing interview with Katie Couric on CBS – were all captured and distributed by mainstream media.

Ironically, the most watched and distributed YouTube content are these clips. What has happened is that Americans are using the viral tools of new media to watch and distribute their own personalized content. Everyone then is becoming their own editor in their own time in their own personalized media environment - thus shattering mainstream media into a hundred million pieces. But Americans are still relying on the core authoritative content of mainstream media to make sense of the election. And this, I think, is the most interesting impact of new media's impact on politics. The internet has made the 2008 election more personalized and democratic – but has still maintained the central role of mainstream media as the chronicler of the key events and central personalities shaping this election.

Today, America and the world are swooning over Barack Obama. This time next year, of course, things may well be very different. The internet, through its interactive technology, has contributed to giving millions of Americans a new sense of ownership and emotional involvement with Obama. Perhaps more than any other Presidential candidate in history, the relationship between Obama and the American electorate is personalized and intimate. At the best of times, this creates a nation united in purpose and direction. But if the economy continues to unravel or nothing really changes politically, the self-congratulatory online crowd can quickly degenerate into an angry mob. That's the danger of today's personalized media in which we are all free to customize our own networks and our own truths. Obama will live and die by the digital sword. On both the Internet and in real life, the next four years in America are going to be essential viewing.

Orginally published on Andrew Keen's blog The Great Seduction. Read Andrew Keen every Monday in the media section of the paper - independent.co.uk/media