Search engine optimization different signals. The leading search engines, Google, Bing, and Yahoo, do not disclose the algorithms they use to rank pages. Some SEO practitioners have studied different approaches to search engine optimization, and have shared their personal opinions. Patents related to search engines can provide information to better understand search engines. In 2005, Google began personalizing search results for each user. Depending on their history of previous searches, Google crafted results for logged in users. In 2007, Google announced a campaign against paid links that transfer PageRank. On June 15, 2009, Google disclosed that they had taken measures to mitigate the
Search Engine Watch Search Engine Watch Search Engine Watch (SEW) provides news and information about search engines and search engine marketing. Search Engine Watch was started by Danny Sullivan in 1996. In 1997, Sullivan sold it for an undisclosed amount to MecklerMedia (now WebMediaBrands). In 2005 the website and related Search Engine Strategies conference series were sold to Incisive Media for $43 million. On November 30, 2006, Danny Sullivan left Search Engine Watch, after his resignation announcement on August 29, 2006. Rebecca Lieb was named editor-in-chief the following month. In 2015, Incisive Media sold SES, Search Engine Watch, and ClickZ to Blenheim Chalcot.