XML feeds are a form of paid inclusion where a search engine is fed information about an advertiser’s web pages by XML. XML
is a data delivery language that stands for “Extensible Markup Language” and allows users to define their own elements for sharing structured data. XML feeds also allow the search engine
to gather information about web pages without having to gather information by crawling through pages. Marketers who are involved with an XML feed pay to have their pages included in a spider-based search index based on a XML format document which represents each advertiser’s websites.