If you're looking at the rise of an Internet startup, it is always good to start with the numbers. According to a recent Newsweek article, YouTube is now serving up more than 30 million video views a day, and receiving about 35,000 video uploads daily from its users. Alexa.com has them ranked as the 32nd most visited site on the net.

So, in a space with plenty of big players, but no real successes, how did start-up YouTube manage to get so big, so fast, and why was it successful where other big players were not? It's the interface, stupid! While the technological and bandwidth barriers to getting video online easily have only just recently ebbed away, YouTube managed to be the first to take advantage of this new opportunity in a way that, quite simply, works. From the beginning, YouTube's main interface, aside from a growing list of minor improvements and additions, has remained structurally unchanged since its inception. This is a good thing, because beyond its massive user base, this interface is YouTube's greatest asset as a content provider.

So let's take a look at that interface, for it has much to say about where the publisher/user relationship (again, heretofore a primarily publisher/viewer relationship) is going. YouTube is a great example of this maturing relationship, where consumers join in the responsibility of publishing and publishers focus on building the best platforms. By employing the latest in social organizing tools like tags and highly coordinated linking options, YouTube's site makes it easy for users to share not only the videos they have uploaded, but also what they think about everything that is already there.

A site full of continuously updated content has the potential to be interesting, sure. But to be truly interesting and entertaining in a medium that grows by 35,000 videos a day, social organization of all that video is key, since without it, there would be no way to keep up with the flood. Much like Flickr, YouTube has tapped into the wisdom of crowds to help it select and filter what users should see, while still catering to a multitude of interests. And you don't have to understand these principals of social organization on any kind of academic or esoteric level, because the interface design itself acts as your personal social organization teacher and guide. With the help of this teacher, YouTube is able to coax its users into forming a kind of self-organizing collective of video processors that not only categorize the site's videos, but also filter and flag that which is unacceptable for the site.P> YouTube's viral factor should be of interest to all those advertisers looking for the latest competitive edge. Successful word-of-mouth campaigns continue to be one of advertising's most effective, yet elusive tools. Banking on the passion and interest of your supporters and customers is a delicate balance that can either foster unparalleled levels of devotion when handled effectively or seriously alienate an audience if the message is too heavy-handed or manipulative. It must be an open relationship where the customer's voice is accepted in good times and bad. And YouTube has created an incredibly fertile environment to let loose such viral endeavors.

But how does an advertiser tap into YouTube's nearly mob-like audience in its embracing of gray-area content and ultra-shortened attention spans? All the cues are to be found in the site itself. Banner advertising or anything else that is going to clutter up the clean, intuitive interface is nowhere to be found. This is because the YouTube team understands what its strong points are, and has until recently relied exclusively on a few Google AdSense strips of context-sensitive text ads. But I believe this is simply a tentative measure as YouTube builds up its audience for its true advertising vehicle - selling video views as a leading Internet video channel.

For me, reading a Hitwise blog post about YouTube surpassing Google Video for video search site market share really brought an important insight to light People are starting to see the traffic on video search sites in the same light as the Nielsen ratings for the major TV networks. And while networks cater to a multitude of demographics based on the content they are showing in a current time slot, the coming Internet TV networks will cater to more specific demographics based on the interface and content they have to offer 24 hours a day.

In the end, the best way for advertisers to take advantage of sites like YouTube will be an age-old idea - know your audience. In a Hollywood Reporter interview, founder Chad Hurley made it clear that YouTube knows its audience, and will take steps to avoid alienating them with any overly corporate messages. "We are moving really cautiously for that reason," Hurley says. "We are looking at indie brands, the kind of brands that resonate with our users." Wider and broader audiences and demographics are being swallowed up by the increasingly participatory culture of the Internet, but for now, the movement represents a market in and of itself. The agencies and advertisers that can speak to this new cultural market on its own terms will find an uncharted realm of media real estate more valuable than anything currently available on old media's prime time.

This commentary is insightful. I recommend it to others.