Seo (Search Engine Optimization) is a set of methods aimed at improving the number and quality of visitors to a website from “natural” or “organic” search engine listing. SEO is a subset of search engine marketing, which also includes sponsored search listings. The term SEO can also refer to “search engine optimizers,” an industry of consultants who carry out optimization projects on behalf of clients. Some commentators, and even some SEOs, distinguish methods used by practitioners as either “white hat SEO” (methods generally approved by search engines, such as building content and improving site quality), or “black hat SEO” (tricks such as cloaking and spamindexing). White hats say that black hat methods are an attempt to manipulate search rankings unfairly.