Google Answers was an online knowledge market offered by Google that allowed users to post bounties for well researched answers to their queries. Asker-accepted answers cost $2 to $200. Google retained 25% of the researcher’s reward and a 50 cent fee per question. In addition to the researcher’s fees, a client who was satisfied with the answer could also leave a tip of up to $100. In late November 2006, Google reported that it planned to permanently shut down the service, and it was fully closed to new activity by late December 2006, although its archives remain available.

Yahoo! Answers is a community-driven knowledge market website launched by Yahoo! on December 13, 2005 that allows users to both submit questions to be answered and answer questions asked by other users. The site gives members the chance to earn points as a way to encourage participation and is based on Naver’s Knowledge iN. As of October 2009, it had 179 million users and over 1 billion question and answers. Google’s closed their competing Q&A service Google Answers in November 2006. On June 11, 2007, Yahoo!’s former questions and answers service, Ask Yahoo!, was formally merged with Yahoo! Answers. Yahoo! Answers has become the second most popular Internet reference site after Wikipedia, according to Comscore.