Google had the capacity to capture everything people did on the site on its logs, a digital trail of activities whose retention could provide a key to future innovations. Every aspect of user behaviour had a value. How many queries were there, how long were they, what were the top words used in queries, how did users punctuate, how often did they click on the first result, who had referred them to Google, where they were geographically … These logs told stories. Not only when or how people used Google but what kind of people the users were and how they thought.

* Steven Levy, In the Plex: How Google Thinks, Works, and Shapes Our Lives