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
Sputnik (search engine) Sputnik (search engine) Sputnik is a web search engine owned by the Russian state-owned telecommunications company Rostelecom. It markets itself as an engine geared towards "local services". At the end of the week of the launch, it was responsible for 0.01% of the search engine traffic in Russia, compared with 62% for Yandex and 28% for Google. It went through the maximum in February 2016, with 11 thousands hits (compared with 121 million hits of Yandex). In January 2017, Sputnik was the 15th most popular search engine in Russia, with 1 / 32,000 times the hits of Yandex. The experts