Newmark resides in San Francisco’s Cole Valley and is active at Craigslist in customer service, mostly dealing with spammers and scammers. In 2009 he became a member of the Wikimedia Foundation advisory board.

Craigslist is a centralized network of online communities, featuring free online classified advertisements with sections devoted to jobs, housing, personals, for sale, services, community, gigs, résumés, and discussion forums. Craig Newmark began the service in 1995 as an email distribution list of friends, featuring local events in the San Francisco Bay Area, before becoming a web-based service in 1996. 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 2009, Craigslist operates with a staff of 28 people. 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 City, Los Angeles, San Diego, Boston, Seattle, Washington D.C., Chicago, Philadelphia and Portland, Oregon and paid broker apartment listings in New York City ($10 per ad).

Andreas Weigend is a former Chief Scientist at Amazon.com and the author of over 100 scientific papers on the application of machine learning techniques to finance and business problems.

He currently lectures at Stanford, Berkeley and Tsinghua Universities on the application of data analysis to electronic business problems. He is an advisor to many technology companies including MySpace and Nokia, and is a limited partner in The Founders Fund.