Nice history of craigslist

"Craig Newmark, its founder, was, and remains, protective of the noncommercial character of the site. In the early years, he ran it in his spare time with the help of other volunteers. Eventually, the traffic overwhelmed them; he quit his day job and imposed fees to pay for full-time stewardship. But he minimized the impact on the community by restricting the new charges to employers in San Francisco who placed job ads. Modest fees for employers in two other cities were added only last year, and only after Mr. Newmark invited Craigslist visitors to comment on the wisdom of the change; there were 3,000 remarks, all posted publicly. Today, 99.2 percent of Craigslist advertisements remain free."

NY Times article

Craigslist traffic is now a FIFTH of eBay's.