What if you woke up one day to find that Google had slipped in popularity and several million users had migrated their searches to Yahoo!, Ask and MSN Live Search, or even one of the newer search engines like Snap.com?

If you look back over time, nothing remains the same forever in the business world. What ever happened to TWA and PanAm, once America's flagship international airlines? Wasn't Sears once the largest player in its class back in the '50s and '60s? Brands like the Edsel Corsair of the '50s and Studebaker-Packard of the '60s are largely unknown to younger audiences today. So it's not unheard of that Google could slip and drop in popularity.

Consequently, should you consider a search marketing plan without Google? Definitely. Every search marketer is a critical thinker and long-term planner and therefore should ponder a Plan B.

The rise of social media and the growth of the blogosphere provide new opportunities for businesses to market themselves online and will indirectly have an effect on search traffic. But first, let's start with the major engines, minus Google.

Other major engines
comScore tells us that 41.7 percent of search engine traffic comes from three networks other than Google: Yahoo, MSN Live Search and Ask. Below is a chart showing the numbers.

Here's a rundown on the major players minus Google.

Yahoo:
Yahoo, which stands for "Yet Another Hierarchical Officious Oracle," was started by two college students in a trailer back in 1994. Originally launched as a directory, it purchased Inktomi in 1996 and became a crawler. Today, Yahoo is recognized globally as a major brand in the information retrieval and online shopping business. Yahoo reaches more than 237 million unique visitors in 25 countries and 13 languages.

MSN Live Search:
Microsoft search started out as a crawler-based search engine in 1997, and it has used a combination of human editors and crawlers to provide search results. In 2005, MSN Search launched its own search crawler, and in 2006 MSN Search became Live Search. Microsoft has been struggling to increase traffic for years, and a recent report from Compete suggests an uptick in traffic due to its position as the default engine in the Vista browser software. Microsoft users queried 757 million searches in April 2007.

Ask:
Founded in 1996 as Ask Jeeves, Ask was acquired by InterActiveCorporation in 2005. Earlier, Ask acquired Teoma in 2001. Ask hopes to increase traffic with its Ask3D version of universal search, which displays results in three columns: search refinement options in the left, organic and paid links in the center and Ask3D in the right column. Ask has 25-30 million monthly users.

Author notes:  Paul J. Bruemmer is director of search marketing at Red Door Interactive. Read full bio .