Alexa Internet, Inc. is an online traffic analysis business headquartered in San Francisco, California, that provides services worldwide. It is an Amazon subsidiary that is 100% owned by Amazon.
Alexa was established as a stand-alone business in 1996 and purchased by Amazon in 1999 for a total of $250 million in cash and shares. On more than 30 million websites across the world, Alexa collects statistics on online traffic, worldwide rankings, and other relevant data. Using a sample of millions of Internet users who use browser extensions, as well as data from websites that have opted to install an Alexa script, Alexa estimates the amount of traffic that a website receives.