Craigslist's Secret

Craigslist is a centralized network of online communities, featuring free classified advertisements (with jobs, internships, housing, personals, for sale/barter/wanted, services, community, gigs, resume, and pets categories) and forums on various topics.

Craigslist was founded in 1995 by Craig Newmark for the San Francisco Bay Area. After incorporation as a private for-profit company in 1999, Craigslist expanded into nine more U.S. cities in 2000, four each in 2001 and 2002, and 14 in 2003. As of November 2006, Craigslist had established itself in approximately 450 cities all over the world.

As of 2007, Craigslist operates with a staff of 24 people.[1] Its sole source of revenue is paid job ads in select cities ($75 per ad for the San Francisco Bay Area; $25 per ad for New York; Los Angeles; San Diego; Boston; Seattle; Washington D.C., Chicago) and paid broker apartment listings in New York City ($10 per ad).

Cragigslist serves over five billion page views per month, putting it in 34th place overall among web sites world wide, ninth place overall among web sites in the United States (per Alexa.com on December 29, 2006), to ten million unique visitors. With over ten million new classified advertisements each month, Craigslist is the leading classifieds service in any medium. The site receives over 500,000 new job listings each month, making it one of the top job boards in the world.[2] The classified advertisements range from traditional buy/sell ads and community announcements, to personal ads and even erotic services.

Reference:
Wikipedia

*Why Your Business Cannot Afford Not to Advertise on Craigslist

*The Benefits of Advertising on Craigslist

*Answering Advertisements on Craigslist

*Affordable Advertising on Craigslist

*Advertising on Craigslist