Alexa Internet

Alexa was an Internet service that measures how many Internet users visit a website. At Alexa.com, people entered a website address and Alexa showed them how well-visited the website is. It can also tell them how its popularity has changed over time.
Alexa had 6 million unique visits monthly.

Alexa was created in 1996 by American businessman Brewster Kahle and Bruce Gilliat.
In 1999, Alexa was bought by Amazon.com for about US$250 million in Amazon stock.
Alexa provided a free API that is used by services and toolbars all around the world to easily display Alexa Rating.

In December 2021, Amazon announced that they will shutdown Alexa. Service was discontinued on May 1st, 2022.

Sources

Other websites
 Alexa 

Category:American websites
Category:Amazon (company)