neutrality means equal treatment, regardless of the content, comes from debates on net neutrality. Neutrality in search is complicated by the fact that search engines, by design and in implementation, are not intended to be neutral or impartial. Rather, search engines and other information retrieval applications are designed to collect and store information (indexing), receive a query from a user, search for and filter relevant information based on that query (searching/filtering), and then present the user with only a subset of those results, which are ranked from most relevant to least relevant (ranking). "Relevance" is a form of bias used to favor some results and rank those favored results. Relevance is defined in the search engine so that a user is satisfied with the results and is therefore subject to the user's preferences. And because relevance is so subjective, putting search neutrality into practice has been so contentious. Search neutrality became a concern after search engines, most notably Google, were accused of search bias by other companies. Competitors and companies claim search engines systematically favor some sites (and some kind of sites) over others in their lists of results, disrupting the objective results users believe they are getting. The call for search neutrality goes beyond traditional search engines. Sites like Amazon.com and Facebook are also accused of skewing results. Amazon's search results are influenced by companies that pay to rank higher in their search results while Facebook filters their newsfeed lists to conduct social experiments. "Vertical search" spam penalties In order to find information on the Web, most users make use of search engines, which crawl the web, index it and show a list of results ordered by relevance. The use of search engines to access information through the web has become a key factor for online businesses, which depend on the flow of users visiting their pages. One of these companies is Foundem. Foundem provides a "vertical search" service to compare products available on online markets for the U.K. Many people see these "vertical search" sites as spam. Beginning in 2006 and for three and a half years following, Foundem's traffic and business dropped significantly due to what they assert to be a penalty deliberately applied by Google. It is unclear, however, whether their claim of a penalty was self-imposed via their use of iframe HTML tags to embed the content from other websites. At the time at which