Alexa Internet

Alexa Internet was founded in April 1996 by Brewster Kahle and Bruce Gilliat.[6] The company's name was chosen in homage to the Library of Alexandria of Ptolemaic Egypt, drawing a parallel between the largest repository of knowledge in the ancient world and the potential of the Internet to become a similar store of knowledge.[7] Alexa initially offered a toolbar that gave Internet users suggestions on where to go next, based on the traffic patterns of its user community. The company also offered context for each site visited: to whom it was registered, how many pages it had, how many other sites pointed to it, and how frequently it was updated.[8]

Alexa's operations grew to include archiving of web pages as they are "crawled" and examined by an automated computer program (nicknamed a "bot" or "web crawler"). This database served as the basis for the creation of the Internet Archive accessible through the Wayback Machine.[9] In 1998, the company donated a copy of the archive, two terabytes in size, to the Library of Congress.[7] Alexa continues to supply the Internet Archive with Web crawls. In 1999, as the company moved away from its original vision of providing an "intelligent" search engine, Alexa was acquired by Amazon.com for approximately US$250 million in Amazon stock.[10]

Alexa began a partnership with Google in early 2002, and with the web directory DMOZ in January 2003.[11] In December 2005, Alexa opened its extensive search index and Web-crawling facilities to third-party programs through a comprehensive set of Web services and APIs. These could be used, for instance, to construct vertical search engines that could run on Alexa's servers or elsewhere. In May 2006, Google was replaced with Windows Live Search as a provider of search results.[12] In December 2006, Amazon released Alexa Image Search. Built in-house, it was the first major application built on the company's Web platform. In May 2007, Alexa changed their API to limit comparisons to three websites, reduce the size of embedded graphs in Flash, and add mandatory embedded BritePic advertisements.

In April 2007, the company filed a lawsuit, Alexa v. Hornbaker, to stop trademark infringement by the Statsaholic service.[13] In the lawsuit, Alexa alleged that Ron Hornbaker was stealing traffic graphs for profit, and that the primary purpose of his site was to display graphs that were generated by Alexa's servers.[14] Hornbaker removed the term "Alexa" from his service name on March 19, 2007.[15] On November 27, 2008, Amazon announced that Alexa Web Search was no longer accepting new customers, and that the service would be deprecated or discontinued for existing customers on January 26, 2009.[16] Thereafter, Alexa became a purely analytics-focused company.

On March 31, 2009, Alexa revealed a major website redesign. The redesigned site provided new web traffic metrics—including average page views per individual user, bounce rate (the rate of users who come to, and then leave a webpage), and user time on website.[17] In the following weeks, Alexa added more features, including visitor demographics, clickstream and web search traffic statistics.[18] Alexa introduced these new features to compete with other web analytics services.

Alexa used to rank sites based primarily on tracking a sample set of Internet traffic—users of its toolbar for the Internet Explorer, Firefox and Google Chrome web browsers.[21][22] The Alexa Toolbar includes a popup blocker (which stops unwanted ads), a search box, links to Amazon.com and the Alexa homepage, and the Alexa ranking of the website that the user is visiting. It also allows the user to rate the website and view links to external, relevant websites. In early 2005, Alexa stated that there had been 10 million downloads of the toolbar, though the company did not provide statistics about active usage. Originally, web pages were only ranked amongst users who had the Alexa Toolbar installed, and could be biased if a specific audience subgroup was reluctant to take part in the rankings. This caused some controversies over how representative Alexa's user base was of typical Internet behavior,[23] especially for less-visited sites.[22] In 2007, Michael Arrington provided examples of Alexa rankings known to contradict data from the comScore web analytics service, including ranking YouTube ahead of Google.[24]

Until 2007, a third-party-supplied plugin for the Firefox browser[25] served as the only option for Firefox users after Amazon abandoned its A9 toolbar.[26] On July 16, 2007, Alexa released an official toolbar for Firefox called Sparky.[27] On 16 April 2008, many users reported drastic shifts in their Alexa rankings. Alexa confirmed this later in the day with an announcement that they had released an updated ranking system, claiming that they would now take into account more sources of data "beyond Alexa Toolbar users".[28][29]

Using the Alexa Pro service, website owners can sign up for "certified statistics", which allows Alexa more access to a website's traffic data.[30] Site owners input JavaScript code on each page of their website that, if permitted by the user's security and privacy settings, runs and sends traffic data to Alexa, allowing Alexa to display—or not display, depending on the owner's preference—more accurate statistics such as total pageviews and unique pageviews.