Craigslist Costs Newspapers $5 Billion In Lost Ads

http://www.mediapost.com/publications/article/206729/craigslist-costs-local-newspapers-5-billion-in-lo.html#axzz2bsbcVWWx

By offering buyers and sellers a free alternative to paid listings in newspapers, online classifieds site Craigslist saved users about $5 billion from 2000-2007, while costing local newspapers the same amount in lost classified advertising revenues, according to a new study by professors at the NYU Stern School of Business and Harvard Business School.
The study, titled “Responses to Entry in Multi-Sided Markets: The Impact of Craigslist on Local Newspapers,” explored the impact of Craigslist by analyzing newspaper publisher results over time, focusing on their degree of reliance on classifieds and the timing of Craigslist entry in their market, among other factors.  
Newspapers that were more reliant on classified revenues saw a bigger drop-off after Craiglist entered their markets.