The changes are driven by today’s 500-channel universe —and its ferocious stepchild, the internet. The internet has radically changed the way we find out about things, and how we decide they’re important.

We’re living in a world where the sheer volume of public speech is expanding exponentially. In our parents’ days, books and TV shows and radio shows were scarce. The problem our parents faced was simply getting access to these precious, rare blasts of culture and ideas. Now the internet has opened the floodgates, drenching the world in a zillion witty bloggers, searing podcasters, instant pundits, and hipsters recording skatepunk video clips on their mobile phones. The audience’s problem has become precisely the reverse: information overload.

This is why blogs and “social” technologies have had such a catalytic impact on media. Bloggers and MySpacers are our filters. They sift through the daily torrent of stuff, then shear off the coolest material and bring it to us. They are the TiVo for our 500-channel mediasphere. The same goes for search tools like Google, or blog-search engines like Technorati: We love them because they tame the six-billion-page internet. RSS — the tool for helping people scan hundreds of blogs quickly each day — became popular for the same reason. These technologies are all fundamentally driven by word of mouth, and there’s nothing we trust more than word of mouth.

But while word of mouth is powerful, it’s also a tricky social force. It doesn’t favour all things equally. Word of mouth tends to produce “power law” effects — in which a small number of websites are granted massive, planet-wide star status, while the vast majority are ignored. The same thing happens to news articles and broadcast segments every day. The vast majority languish in obscurity. But once one of them becomes slightly popular online, it instantly becomes massively so — as word of mouth quickly takes off like a brush fire, with each digital neighbour passing it along to her friends. That’s why we see so many books and websites become famous for intense, short periods, often only a day or two at a time. Remember the “Lazy Sunday” video? Or the “Hamster Dance”? They came out of nowhere, flared brilliantly, then vanished.

This winner-take-all effect is only going to become more and more pronounced as the internet matures, because new tools gives us more ways to reach out, tap each other on the shoulder, and say hey, check this out! Mobile devices, which are becoming more and more video-and-internet equipped, will soon amplify this pass-around culture. Social-networking sites like MySpace will become ever more a part of life.

What does this mean for journalism?

It means that the newspapers and broadcasts and magazines that open themselves up — that make it easy for the audience to pass them around and share them — will thrive. Those that close themselves off to the audience’s cut-and-paste culture will slowly die. Want proof? Compare the Christian Science Monitor and The Wall Street Journal. The Monitor has a hard copy circulation of barely 71,000, a pale shadow of the Journal’s mammoth two million readers. But online, the Monitor dominates: It is proportionately 377 times more frequently linked-to than the Journal. That means it enjoys proportionately far higher traffic, far higher online influence, and far more attention from search engines like Google.

How did the Monitor accrue this advantage? By being promiscuous. The Monitor leaves all its stories permanently online for free, while the Journal locks its behind a pay-to-see wall. Bloggers thus almost never link to Journal articles, while they love to link to Monitor articles. Because it makes itself so amenable to blogging culture, the Monitor taps into pass-around culture and these rolling cascades of popularity. (Granted, the Journal is undoubtedly assuming that what it loses in online audience it gains, financially, by having a more exclusive readership. But that’s no way to influence the world, when the world now lives online. And given the steady migration of advertising online, it may not even be the soundest financial ploy.)

So this is how journalists in the future will capture the protean attention-span of society: They’ll make it easy for the online world to engage with them.

And, interestingly, they won’t try and dictate what the most “important” stories are. Indeed, they’ll have to relinquish the very idea that they have the cultural inside track — that they are the ones dictating the agenda of society’s attention span. That’s because the internet has a way of figuring out what it finds most interesting - and half the time it’s never what we journalists would expect. In the U.S., Washington writers pretty much ignored a racist comment by Senator Trent Lott until political blogs began transcribing his words and passing them around online. It turned into an enormous cultural conversation, and the mainstream media eventually started reporting on it. In the end, Lott was so discredited that he resigned as Senate majority leader.

So here’s the future of journalism: You show up at work having no idea whether the article or broadcast you’re working on will sink into total obscurity, or rocket into planet-wide notoriety. What’s going to pop? That piece on insurance-rate gouging? Trucking garbage over the border? Inuit throat singers? One thing is sure: The more promiscuous we make the news — the easier it is for the online audience to sample, pass around, cut up, remix — the more likely it’ll gain online currency.

It’ll also transform the practice of journalism itself. Ask writers who blog regularly (like me), and they’ll tell you how exciting it is to be wired in directly to your audience. They correspond with you, pass you tips, correct your factual blunders, introduce you to brilliant new ideas and people. The internet isn’t just an audience: It’s an auxiliary brain. But you have to turn it on, and it takes work. You can’t fake participation and authenticity online.

So that’s a little road map to the immediate future. But I can’t take you any further than that. That’s because the mediasphere today is driven by new online tools like blogs and RSS, and it’s virtually impossible to predict what new tools we’ll have in the future. Go back 10 years — hell, go back three years — and no one predicted the enormous influence of Napster, instant messaging, blogging, the iPod, MySpace, or Amazon’s “people who bought this book also bought [this book]” suggestions. The only thing I can predict is that things will change: Some kid in her dorm room will invent a new way of sharing information online, and we’ll all scramble to get used to it.

So, yep — the bestseller is dead. Our ability to dictate the national conversation is dead. It’s now in the hands of the swarm intelligence of the internet. Some will mourn this, many will complain about it, but I think we journalists are simply in a new and much more interesting place.

Now we’re part of the audience.