Groupon Changes Privacy Policy, Starts Tracking User Location
readwrite.com/2011/07/11/groupon_changes_privacy_policy_starts_tracking_use
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
The biggest change that Groupon made to its privacy statement was in how it tracks and uses the mobile location data it collects when consumers are using Groupon Now, a function that brings timely deals to users based on the time of day and their location