Search Engine Optimisation – META Engines

Something that isn’t discussed that much in the topic of search engine optimisation are the META-engines. In fact unless you are a search engine optimiser I would doubt you have ever heard this phrase used before.
So What Are They?

In basic terms a META search engine is a tool that does not compile it’s own database of information. It combines the results of a number of search engines at the same time and gives them to you in a comprehensive results page. This has an effect of slowing the results but is a more informative list of results.
A language request is sent to multiple search engines each one directed to deliver results based on the searchers request. This is a very effective way for a searcher to find the precise piece of information they were looking for by covering a vast amount of search information.
How do they work?

Up until this point you are probably under the impression that search engines such as Yahoo! or Google index every single web page that is submitted however this is not true. There are many page factors that will prevent a page from being indexed and therefore META search engines become very interesting as they produce results from multiple information centres.
Just so you can see for real how this works you should visit http://www.metacrawler.com/ and http://www.mamma.com/ , two great examples of meta search engines.
This may be a small part of search engine optimisation but it is worth while having a little knowledge.