The following charts demonstrate how each major search engine and directory relates to each other.
Chart Key
Search Providers: These are listed at the top of each column. Read down to see what they power at major search engines. Click on their names to learn more about them. The most significant providers are listed first, in terms of the reach they have across the major search engines.
Search Engines: These are listed at the beginning of each row, in order of "search hour" popularity, as ranked by Nielsen/NetRatings.
Search engines with more than 2 million search hours per month come first and are shaded dark orange. Partnerships with these search engines thus counts for more importance than with others.
Search engines with more than 1 million search hours per month are shaded light orange, then those with more than 200,000 search hours are shaded light blue.
Those shaded in gray have no significant search hours reported, but they are shown because of the name recognition they may have among serious searchers.
Main: Indicates that a search provider provides the "main" editorial results to a particular search engine, the most dominant listings that will be seen.
Paid: Indicates that a search provider provides paid listings to a particular search engine.
Backup: Indicates that a search provider provides the "backup" results that appear in cases where a search engine's main results fail to find good matches.
Option: Indicates that information from this source is made available either on results pages or in other ways, though the prominence of the information may not be high.
