Search engines use complex mathematical algorithms to interpret which websites a user seeks. In this diagram, if each bubble represents a website, programs sometimes called spiders examine which sites link to which other sites, with arrows representing these links. Websites getting more inbound links, or stronger links, are presumed to be more important and what the user is searching for. In this example, since website B is the recipient of numerous inbound links, it ranks more highly in a web search. And the links "carry through", such that website C, even though it only has one inbound link, has an inbound link from a highly popular site (B) while site E does not. Note: Percentages are rounded.
Small businesses also use social networking sites to develop their own market research on new products and services. By encouraging their customers to give feedback on new product ideas, businesses can gain valuable insights on whether a product may be accepted by their target market enough to merit full production, or not. In addition, customers will feel the company has engaged them in the process of co-creation—the process in which the business uses customer feedback to create or modify a product or service the filling a need of the target market. Such feedback can present in various forms, such as surveys, contests, polls, etc.
Website owners recognized the value of a high ranking and visibility in search engine results, creating an opportunity for both white hat and black hat SEO practitioners. According to industry analyst Danny Sullivan, the phrase "search engine optimization" probably came into use in 1997. Sullivan credits Bruce Clay as one of the first people to popularize the term. On May 2, 2007, Jason Gambert attempted to trademark the term SEO by convincing the Trademark Office in Arizona that SEO is a "process" involving manipulation of keywords and not a "marketing service."