Odnoklassniki (Russian: Одноклассники, lit. 'Classmates'), abbreviated as OK or OK.ru, is a social network service used mainly in Russia and former Soviet Republics. The site was launched on March 4, 2006 Albert Popkov and is currently owned by VK. The website currently has more than 200 million registered users and 45 million daily unique visitors. Odnoklassniki also currently has an Alexa Internet traffic ranking of 56 worldwide and 7 for Russia. Odnoklassniki is the second most popular social network in Russia, behind VK (VKontakte) but ahead of Facebook, which is in 3rd place. From Wikipedia
