Of course Danny Sullivan"s Universal Search primer is the most comprehensive resource on the topic, but Manoj offers up links to more than a dozen other author"s coverage as well.

I"ve been thinking about this issue myself in the last week or so, especially while playing around with Ask"s new Ask 3D interface. As I see it, the shift toward integrated vertical search results makes it pretty clear that the companies that wish to continue living in their own little "we can control our web site" comfort zone are going to be forced to start dipping toes into the social media waters.

There are two key things at play here.

First, with the introduction of integrated content, there are no longer ten "organic" search listings. Mix in a few videos from YouTube, some news results, local business listings and so on and you"ve suddenly used up a couple of those essential listings.

That means there are now LESS chances for your company to rank on the first page with traditional web site content.

On the other hand, the addition of those video listings, news results, local business listings and so on suddenly means you have MORE chances to rank on the first page of results.

For example, look at this Google results listing for the term "rayco tree mower."

You might notice that the first two listings are YouTube videos. Those videos were posted by Matt Bailey on his Site Logic Marketing blog earlier this year. With those two videos now taking up the top two spots in the search results, there are just eight organic results left to be filled. If Rayco had posted those two photos and had managed to pull a double listing for their own site, they would have captured four of the top ten listings.

That"s not bad.

In fact, I hold three of the top ten listings for a search on a product name of something I reviewed on the Lactivist site. I have two posts that are showing in the #3 and #4 spot and a YouTube video of the product ranking in the #5 spot.

I suppose Google could promote Universal Search like a sweepstakes contest..."Now with more chances to win!...err...Rank!"

The point here is that over time, these vertical search results are going to continue to creep in to the results at the major search engines. If you aren"t making sure that you have original content showing up (and optimized) in each of the vertical channels that are being integrated, you not only miss out on the chance to score more rankings and traffic, you also leave the door wide open for your competition to come in and snuff out your presence.