ISAPI Filters allow you to customize the behavior of an IIS web server. The Search Engine Friendly Filter allows you to disguise dynamic pages as static pages, helping to ensure that they are analyzed by search engines.
The Search Engine Friendly Filter has two tasks which it performs. Between them, these tasks allow dynamic web site content to appear as completely static. A number of search engines these days will catalog dynamic content, but even for those engines which do, a static page is 10 to 100 times more likely to be cataloged than a dynamic page.
Disguise dynamic content as a directory structure
Ability to cope with part of the query string disguised and part standard
Convert file extensions, for instance disguise ASP files as HTML files
Easy installation and administration
Apply to all web sites on a server, or only selected sites
In this day and age, two things determine how highly a web site is ranked in search engines. Relevant content, and links from other relevant sites. But the only way to determine these things is by scanning the content of your web site, and if you have a lot of dynamic content, most search engines will not notice it.
By adding the Search Engine Friendly Filter to your web site, you can assist the search engines in finding the important content they are searching for. This helps both you and them by directing interested people to your site. And that's what you really want, people visiting your site that are interested in what you have to offer.