Webmasters always anxiously wait for a search engine update. Those who rank well want to see their sites get even better. Those who didn't do well expect a major boost. Those whose sites get de-indexed anticipate a major comeback. Those who just started new sites bet on their sites will make into the first page of search engine result pages (SERPs) for their targeting keywords. Of course, not everyone will be happy about the results of search engine updates. After all, search engine traffic is a zero-sum game - someone loses and someone gains. Then, the webmasters start preparing for next update.
The Types of Search Engine Updates
Search Engines are large software systems. There're three types of search engine updates.

1. Updates of index database - Search engine crawlers continuously scan the Web for new content and changes to feed their index databases. This drives the minor SERP shifts.
   
2. Minor search engine updates - Search engines need to fix software bugs and do some minor algorithm changes once in a while. Minor updates seem to happens monthly.
   
3. Major search engine updates - Every year, major search engines will shock the SEO community with major search engine updates. A major update involves both major algorithm changes and the re-organization of the index database. Major search engine updates are clearly driven more by business reasons than by technical reasons.

The Business Reasons Behind The Major Updates
All major search engines claim that they strive to present search results to users with the highest quality. But the business of search engine is business. What they won't tell us is that there're many business reasons for every major search engine updates. Search engine traffic is hot commodity - it's free and has higher conversion rate since the searchers are very close to make their buying decisions. The downside of the search traffic for webmasters is that they don't have control at all. Your sites may be ranked #1 today, but nowhere next day.
Search engine companies will, no doubt, use the search engine traffic to maximize the values for their stakeholders. Google's Feb. 2 update (allegra update or Superbowl update) once again shocked the webmaster community like last Florida update. The noticeable change in Superbowl update is that well-established sites rank well even for specific keywords that aren't even highly relevant to their pages. You may think the move is to fight spams and improve the quality of SERPs. That's only part of the story. The results of the update is that the websites of well-established corporations (with never ending press releases) will get a major traffic boost from Google. Google does this by algorithm changes, not manual manipulations.
If we think search engine traffic from Google is really an incentive to try it free before you buy. This time, Google decides to lure the major corporations to test the benefits of search traffic. Major corporations will likely increase their spending in online advertising and those news agencies may even drop their law sues against Google if they see the traffic from Google justifies that their sites benefit from including in Google index database.
Is this the real driving force behind last update? Only Google knows. If you own Google, however, you will do the exactly the same.
Will this negatively impact the user experience? - maybe and maybe not. What is the real difference between the #1 spot and the site that ranks #100? - the backlinks. Backlinks don't alter the quality of a page at all.
When they say technology, they mean business. Major technology changes are always driven by business needs. It has nothing to do with "good" or "bad".
Strategies to Cope with search Engine Updates
The Internet and the Web was once hailed as the new medium and the new opportunity for small business and site owners. They will be disappointed as big three peek into fortune 500 companies's deep packets. There're strategies they can use to cope with the search engine updates, however.

1. Create a portfolio of website using different SEO techniques. If some of your sites get hammered in a update the rest may benefit from the update.
   
2. Generate traffic from all major search engines.
   
3. Use the search traffic to build loyal user bases.
   
4. Build sites similar to the sites of well-established companies. The tags, on-page, off page optimization techniques will become less and less important as major corporations aren't interested in those types of things that geek webmasters are interested.

Speculation on Coming Updates
The next Google update is around the corner. I won't expect any noticeable change. If Google decides to let big apples try search traffic free. They will need a couple of months to realize the values of the search traffic. There will be major re-distribution of search traffic in 3 or 6 months. If the same group of major corporations always get huge amount of free traffic from Google. They won't bother to open their wallets. The major traffic distribution may be from one group of major corporations to another. The search traffic will unlikely sift back to small sites.
Copyright Bruce Zhang 2005

About The Author

Bruce Zhang operates a website http://www.4th-media.com that automatically aggregates and categorizes SEO news, new articles, and forum threads from over 50 sources daily ( http://www.4th-media.com/newsbot/ ) to help webmasters and SEO professionals to keep up with the latest development in search engine marketing. The website also offers original thoughts on SEO.