Craigslist is a supremely popular listings site. Craigslist was founded by Craig Newmark in March 1995 as an email list site for San Francisco and Bay Area events. In June 2000, it added its second city, Boston, and then expanded to the major metropolitan cities in August 2000. As of July 2014, Craiglist covers more than 700 local sites in 70 countries.
Craiglist.org — note the .org domain suffix — is interesting in that it serves no ads and stresses a non-corporate culture. It has only 40-some employees, all based in San Francisco, and makes money off job ads in 10 cities, as well as brokered apartment listings in NYC.
Founders: Craig Newmark