Paid Inclusion is and Internet advertising program where your website is guaranteed to be included in a Search Engines Index in exchange for a payment. The most popular types of Paid Inclusion is the use in larger Web directories, such as Business.com or Yahoo.com.
A type of advertising programme where organisations pay in order to be included in a Search Engine's index or to be included more quickly, though there is generally no guarantee of the subsequent ranking in the results pages. Overture's Site Match is an example of this.
Many search engines offer a PFI program to assure frequent spidering or indexing of a site (or Web page). PFI does not guarantee that a site will be ranked highly (or at all) for a given search term. It just offers webmasters the opportunity to quickly incorporate changes to a site into a search engine's index.