Andrew Ellam, “Overture and Google: Internet Pay per Click (PPC) Advertising Auctions,” London Business School, March 2003, http://www.kellogg.northwestern.edu/Faculty/ottaviani/homepage/Papers/Overture%20and%20Google.pdf (accessed June 23, 2010).
“Financial Release,” press release, Google, January 31, 2008, http://www.google.com/intl/en/press/pressrel/revenues_q407.html (accessed April 3, 2008).
“Google Announces Plan for Two-Year Expiration, but…,” Google Watch, July 16, 2007, http://www.google-watch.org/cgi-bin/cookie.htm (accessed April 3, 2008).
“Google Search’s Golden Triangle,” Eyetools, http://www.eyetools.com/inpage/research_google_eyetracking_heatmap.htm (accessed April 3, 2008).
“Search Engine Results Chart,” Search Engine Watch, March 23, 2007, http://searchenginewatch.com/2167981 (accessed June 18, 2010).
Danny Sullivan, “Searches per Day,” Search Engine Watch, April 20, 2006, http://searchenginewatch.com/2156461 (accessed June 18, 2010).
“Traffic History Graph for Google.com,” Alexa, April 3, 2008, http://www.alexa.com/data/details/traffic_details/google.com (accessed April 3, 2008).