All of this goes back to each business's core focus. For Google, everything is search; Yahoo and MSN, by contrast, work in many channels at once and look to integrate them. And because MSN and Yahoo are already thinking about integration now, they'll be far better prepared when integration really get underway.

You can see that philosophical divergence in the way each entity picks up search traffic. Google's name is synonymous with search, and it's the search engine itself that drives the bulk of Google's search traffic base. Yahoo also gets plenty of direct-to-search visitors; but an awful lot of Yahoo search traffic arrives off of search bars on Yahoo's enormous publisher network. The same is true for MSN and its publisher network-and MSN searchers even arrive via help buttons on Microsoft software. Google is popular for search in its own right; Yahoo and MSN Search owe much of their popularity to the way each business draws users from its enormous, diverse universe of user interfaces.

The different philosophies also come out in how each business applies search thinking to non-search channels. To take one example, consider search-influenced solutions for content/publisher sites. Google's big accomplishment here is AdSense, which syndicates actual search ads onto content pages. Yahoo's Publisher Network isn't so different from AdSense; but Yahoo has also bought into the Right Media Exchange--which will let the Yahoo publisher network sell display ads by auction, just as Yahoo already does for search ads. Meanwhile, MSN's publisher network is beginning to offer targeting on a level that's clearly inspired by the thinking behind AdCenter, MSN's super-targeted search platform.

These are very different approaches to how search might help publishers and content sites. Google's AdSense effectively recreates the world in the image of search. MSN and Yahoo, by contrast, truly integrate very different models, combining elements of text-based search advertising with image-based publisher advertising to make something new.

Which approach--Google's search-centric approach or MSN/Yahoo's integrative one--is better? A snapshot of today's online market would give a resounding win to Google, which pulls in roughly 25% of all online ad revenue, the vast majority of which comes from search. Google's win is strengthened by Yahoo's poor Q3 performance, especially given the fact that analysts agree that it's Yahoo publisher network, not its search network, that's giving Yahoo trouble.

But a present-day snapshot is misleading. That's because the information world of today is siloed in a way that tomorrow's world won't be. Full-length TV content that lives online, and iTunes for your cell phone, are just the beginning of the new convergence--and as channels continue to converge, the ability to work in many universes at once will be increasingly critical. Which is why the multichannel model, and not the search-only model, might just be the long-term winner.

There's even some indication that the tide's already turning. That indication comes from online video, which is effectively the merger of the Internet and TV. Just two days after the YouTube acquisition, an Oct. 11 Businessweek article ranked Google Video as the fifth-most popular video destination on the Web--with MSN Video as No. 4, and Yahoo Video at No. 1. Online video is the merger of different media models, and it's the integrators, not the dominators in search, who took the lead.

Of course, Google may have solved its video problems by purchasing YouTube. But if Google's video problems come from too narrow a focus on search, then one needs to wonder how many billion-dollar fixes Google can buy just to stay on top as the landscape shifts. Which is why if Google can't develop a more convergence-minded view of the world, it could face real trouble from a new Microhoo that's convergence-minded enough, and large enough, to win in Web 3.0.

This commentary is insightful. I recommend it to others.