The main types of social networking services are those which contain category places (such as former school year or classmates), means to connect with friends (usually with self-description pages) and a recommendation system linked to trust. Popular methods now combine many of these, with Facebook and Twitter widely used worldwide, Nexopia (mostly in Canada);[1] Bebo,[2] VKontakte, Hi5, Hyves (mostly in The Netherlands), Draugiem.lv (mostly in Latvia), StudiVZ (mostly in Germany), iWiW (mostly in Hungary), Tuenti (mostly in Spain), Nasza-Klasa (mostly in Poland), Nyx.cz (mostly in Czech Republic), iCubee (mostly in Philippines), Decayenne, Tagged, XING,[3] Badoo[4] and Skyrock in parts of Europe;[5] Orkut and Hi5 in South America and Central America;[6] and Friendster, Mixi, Multiply, Orkut, Wretch, renren and Cyworld in Asia and the Pacific Islands and LinkedIn and Orkut are very popular in India.
There have been attempts to standardize these services to avoid the need to duplicate entries of friends and interests (see the FOAF standard and the Open Source Initiative). A 2011 survey found that 47% of