Name	Description/Focus	Registered users	Registration
Adult FriendFinder	Adults Only Dating/Hookup Network	33,000,000	Open
Advogato	Free and open source software developers	13,575	Open
affluence	Ultra wealthy and social elite	25,000	Open, activation upon verification
Amie Street	Music		Open
ANobii	Books		Open
aSmallWorld	European jet set and social elite	270,000	Invite-only
Athlinks	Running, Swimming, Cycling, Mountain Biking, Triathlon, and Adventure Racing	54,270	Open
Avatars United	Online games.		Open
Badoo	General, Popular in Europe	13,000,000	Open to people 18 and older
Bahu	General, Popular in France, Belgium and Europe	1,000,000	Open to people 13 and older
Bebo	General.	40,000,000	Open to people 13 and older
Biip	Norwegian Community.		Requires Norwegian phone number.
BlackPlanet	African-Americans	20,000,000	Open
Broadcaster.com	Video sharing and webcam chat	322,715[21]	Open
Buzznet	Music and pop-culture	10,000,000[22]	Open
CafeMom	Mothers	1,250,000[24]	Open to moms and moms-to-be
Cake Financial	Investing		Open
Care2	Green living and social activism	9,961,947[26]	Open
Classmates.com	School, college, work and the military	50,000,000[27]	Open
Cloob	General. Popular in Iran.		Open
College Tonight	College students.		requires an e-mail address with an ".edu" ending
CouchSurfing	Worldwide network for making connections between travelers and the local communities they visit.	1,017,429[29]	Open
CozyCot	Social networking site for women from South East Asia (especially Singapore), East Asia, North America and Australia.		Open
DeviantART	Art community	9,040,962[31]	Open
dol2day	Politic community, Social network, Internet radio (German-speaking countries)	40,200[33]	Open
DontStayIn	Clubbing (primarily UK)		Open
Elftown	Community and wiki around Fantasy and sci-fi.	185,000[34]	Open, approval needed
Epernicus	For research scientists		Open
Eons.com	For baby boomers		Open to people 13 and older
Espinthebottle	Teen networking site offering photos, games, and relationships		Open to people 13 and older
Experience Project	Life experiences		Open
Facebook	General.	200,000,000[36]	Open to people 13 and older.
Faceparty	General. Popular UK.	200,000[38]	Invitation only to people 18 and older.
Faces.com	British teens		Open to people 13 and older
Fetlife	People who are into BDSM	32,500[40]	Open to people "of [legal] age to see adult content"
Filmaffinity	Movies and TV Series	250,000[42]	Open
Flixster	Movies	63,000,000[44]	Open to people 13 and older
Flickr	Photo sharing, commenting, photography related networking, worldwide		Open
Fotolog	Photoblogging. Popular in South America and Spain.	20,000,000[47]	Open
Friends Reunited	UK based. School, college, work, sport and streets	19,000,000[49]	Open
Friendster	General. Popular in ASEAN countries.	90,000,000[51]	Open to people 16 and older.
Frühstückstreff	General		Open
Fubar	dating, an "online bar" for 18 and older	1,200,000[53]	Open
Gaia Online	Anime and games		Open to people 13 and older
Gather.com	Article, picture, and video sharing, as well as group discussions	465,000[55]	Open
Geni.com	Families, genealogy	15,000,000[56]	Open
Goodreads	Library cataloging, book lovers		Open
Gossipreport.com	Anonymous gossip		Open to people 16 and older
Grono.net	Poland		Open
Habbo	General for teens. Over 31 communities worldwide. Chat Room and user profiles.	117,000,000[58][59][60]	Open to people 13 and older
Helium.com	Writing social community.	400,000	Open to people 13 and older
hi5	General. Popular in India, Angola, Portugal, Cyprus, Romania, Thailand, Central Africa and Latin America.	80,000,000[63]	Open to people 13 and older
Hospitality Club	Hospitality	328,629[65]	Open
Hyves	General, Most popular in the Netherlands.	8,000,000[66]	Open
imeem	Music, Video, Photos, Blogs	24,000,000[68]	Open
Indaba Music	Online music collaboration, remix contests. Users in 175 countries.	125,000[70]	Open
IRC-Galleria	Finland	505,000[72]	Open to Finnish speaking people 12 and older
Italki	Learning languages, and helping others to learn	350,000	Open
InterNations	International community		Invite-only
itsmy	Mobile community worldwide, blogging, friends, personal TV-shows	2,500,000[74]
iWiW	Hungary	1,700,000[75]	Invite-only
Jaiku	General. Owned by Google.		You must request an invitation into the beta-test
Jammer Direct	Creative resource website		Open to the General Public
kaioo	General, nonprofit	30,000[76]
Kaixin001	General. In Simplified Chinese; caters for mainland China users		Open to the General Public
Last.fm	Music	21,000,000[77]	Open to people 13 and older
LibraryThing	Book lovers	400,000[79]	Open to people 13 and older
lifeknot	Shared interests, hobbies		Open to people 18 and older.
LinkedIn	General but mainly business	35,000,000[80]	Open to people 18 and older.
LiveJournal	Blogging	17,564,977[82]	Open (OpenID)
Livemocha	Languages. Used to learn and help others learn languages.	1,000,000[84]	Open
LunarStorm	Sweden	[86]	Open
MEETin	General		Open
Meetup.com	General. Used to plan offline meetings for people interested in various activities.		Open to people 18 and older.
Meettheboss	Business and Finance community, worldwide.		Open
Mixi	Japan	20,936,509[87]	Invite-only
mobikade	mobile community, UK only		Open to people 18 and older
MocoSpace	mobile community, worldwide	3,000,000[89]	Open to people 14 and older
MOG	Music		Open to people 14 and older
Multiply	"Real world" relationships	10,000,000[90]	Open to people 13 and older
Muxlim	Muslim portal site	50,000[92]	Open to people 13 and older
MyAnimeList	Anime themed social community	160,000[94]	Open to people 13 and older
MyChurch	Christian Churches	144,295[96]	Open
MyHeritage	family-oriented social network service	30,000,000 [98]	Open
MyLOL	General. Popular in the United States, Europe and Australia.	32,000[100]	Open to ages 13 and up.
MySpace	General.	253,145,404[102]	Open to ages 13 and up.
myYearbook	General	5,100,000[103]	Open to age 13 and up & Grades 9 and up
Nasza-klasa.pl	School, college and friends. Popular in Poland.	12,000,000[105]	Open
Netlog	General. Popular in Europe and Québec province. Formerly known as Facebox and Redbox.	42,000,000[106] [107]	Open to people 13 and older
Nettby	Norwegian Community.		Open
Nexopia	Canada	1,400,000[109]	Open to people 14 and older
Ning	Users create their own social websites and social networks		Open
Odnoklassniki	General. Popular in Russia and former Soviet republics	33,000,000	Open
OkCupid	Social networking and dating		Open to people 18 and older
OneWorldTV	Not for Profit Video sharing and social networking aimed at people interested in social issues, development, environment, etc.		Open
Orkut	Owned by Google. Popular in Brazil, Paraguay, India, Pakistan and Estonia.	67,000,000[112]	Open to people 18 and older, (Google login)
OUTeverywhere	Gay/LGBTQ Community		Open
Passportstamp	Travel		Open
Pingsta	Collaborative platform for the world's Internetwork Experts		Invite-only, only Internet Experts
Plaxo	Aggregator	15,000,000[114]	Open
Playahead	Swedish, Danish,Norwegian teenagers		Open
Playboy U	Online college community		Open to college students with .edu e-mail address
Plurk	Micro-blogging, RSS, updates		Open
quarterlife	A social network for artists, filmmakers, musicians, and creative people		Open to people 14 and older
Ravelry	Knitting and crochet	331,000[116]	Invite-only while in beta
Reunion.com	Locating friends and family, keeping in touch	51,000,000[117]	Open
ResearchGATE	Social network for scientific researchers	30,000	Open
Reverbnation	Social network for musician and bands	25,000	Open to people 16 and older
Ryze	Business	500,000[119]	Open
scispace.net	Collaborative network site for scientists		By invitation, but can request an invitation
Shelfari	Books		Open
Skyrock	Social Network in French-speaking world	22,000,000[120]	Open
SocialVibe	Social Network for Charity	435,000	Open
Sonico.com	General. Popular in Latin America and Spanish and Portuguese speaking regions.	17,000,000[122][123]	Open to people 13 and older.
Soundpedia	Music		Open	]
Spoke	Business networking		Open
Stickam	Live video streaming and chat.	2,000,000[127]	Open
StudiVZ	University students, mostly in the German-speaking countries	8,000,000[128]	Open
Tagged.com	General	70,000,000[129]	Open
Talkbiznow	Business networking		Open
Taltopia	Online artistic community		Open
TravBuddy.com	Travel		Open
Travellerspoint	Travel		Open
tribe.net	General		Open
Trombi.com	French subsidiary of Classmates.com	4,400,000[133]
Tuenti.com	General. Very Popular in Spain		Invite-only
Twitter	Micro-blogging, RSS, updates	2,200,000 [135]	Open
V Kontakte	Russian social network.	31,836,000[137]	Open
Vampirefreaks	Gothic and industrial subculture	1,931,049[139]	Open to users 13 and over
Viadeo	European Social Networking and Campus Networking in Seven Languages	6,000,000[140]	Open
Vox	Blogging		Open
Wasabi	General		Open
WAYN	Travel and lifestyle	10,000,000[142]	Open to people 18 and older
WebBiographies	Genealogy and biography		Open
Windows Live Spaces	Blogging (formerly MSN Spaces)	120,000,000[144]	Open
Wis.dm	Questions and answers about anything and everything	50,000[146]	Open
WiserEarth	Online community space for the social and environmental movement[147]	20,600[148]	Open to people 18 and older
Xanga	Blogs and "metro" areas	27,000,000[150]	Open
XING	Business (primarily Europe (Germany) and China)	6,000,000[152]	Open
Xiaonei	Significant site in China	15,000,000[154]	Open
Xt3	Catholic social networking, created after World Youth Day 2008		Open
Yammer	Social networking for office colleagues		Must have company email
Yelp, Inc.	Local Business Review and Talk		Open
Youmeo	UK Social Network (focus on data portability)		Open
Zoo.gr	Greek Web Meeting point	890,000[155]	Open