Blended search, also known as universal search, is starting to change the way searchers see search results—and consequently, the way search marketers and Web site owners approach search marketing.

Much of the search strategy has revolved around textual content and keywords on Web sites and getting links to sites.

Not only has content expanded to include video and audio, but the content format itself has also evolved—personal Web sites, basic brochure-ware company sites, and simple ecommerce have been joined by forums, blogs, review sites, social media, and more.

Over time, the search engines began developing specialty search spiders that focused on various subsets of the online world to handle this additional content and formats.

Searching for and indexing specific content could be fine-tuned to account for the challenges and nuances of the medium, as well as allow searchers to locate this content easier. Searches for news, blogs, products, images, videos, or other content could be handled differently, and hopefully better than, through regular searches.

Though the search engines built special vertical searches, not many searchers came, at least not in the overall scheme of things. Regardless of what people were searching for, the majority of searchers continued to perform searches through the "standard" web search interfaces.

In fact, most searchers, even today, are probably fairly oblivious to the various specialty, or vertical, search indexes. In part, this helps explain some of the rationale that lead to blended search.

So what is blended search? Blended search involves blending different content from the engine's various vertical indexes into the traditional, standard search results. Search results may include special news results, images, videos, maps, blog posts, product listings, patent information, or financial details alongside the usual search results.

Some of this content may have shown up before; but unlike the traditional listings, results from a vertical index used in blended search may be called out and labeled based on the type of content it is.

All of the major search engines have now integrated blended search into their standard search results. How noticeable this is varies from engine to engine and often by specific search query. The impact may still be very subtle as the engines slowly and carefully roll out this change.

This isn't too surprising, considering that this is one of the biggest changes affecting the type of search results that people have grown accustomed to. Obviously the engines don't want to overwhelm searchers with too much change.

What blended search clearly means, however, is that search marketing strategy is taking on an even greater focus than ever before... and there's a need to diversify, diversify, diversify your content.

Most search result pages deliver 10 organic (or natural) results along with some paid-search results. Search engines are implementing blended search in different ways. In some cases, these blended results are being added in addition to the traditional search results, but in other cases some of the blended results actually replace the traditional results.

That last method is especially important, as it means that although only 10 results are still being delivered, their makeup has changed.

What does this mean for you and your site, now and in the near future? If you aren't diversifying your content and targeting these other vertical search areas, you are missing out on additional opportunities to rank, and may even be losing positioning—which could happen if the addition of blended results bumps your listing off page one.

And don't think that you only have to worry about being bumped if you are in the number-10 position. The search engines may simply bump all listings down, or the spot where the blended search result is inserted may be the one that gets bumped off page one.

Diversifying your content strategy is not only a defensive move but also an offensive one: The more content you have that may fit into the different search verticals, the more you increase your chances for ranking.

How to specifically target blended search as an opportunity varies for everyone, every site, and every industry.

The first step, though, is to get a feel for how blended search is affecting searches within your industry today:

• Perform searches in Google, Yahoo, MSN and Ask that relate to your industry, or searches that you would like to be found for, and look over the results.
• Also perform searches for popular, general phrases in case your specific searches don't yet demonstrate blended search results.
• Make notes about the blended results you see, such as when videos show up, news posts, maps and local listings, etc.

Blended search is being introduced so subtly that you may not even notice without making a conscious effort. It's going to continue to evolve, so recognizing it today, getting an understanding of what it means for your industry.

Refining your content-diversification strategy today will put you in good stead for the future.