https://www.gamespot.com/articles/overwatchs-new-social-features-detailed-includes-e/1100-6459432/

Blizzard has announced a number of new social features that are coming to Overwatch: Endorsements and Looking For Group. As explained in the latest Overwatch developer update, Endorsements allow people to recognise gameplay behaviours from players on both their own and the enemy team.

There are three categories of behaviour that someone can be highlighted as excelling in: Sportsmanship, Good Teammate, and Shot Caller. Those that maintain a high endorsement level will be periodically rewarded, but game director Jeff Kaplan did not reveal what these rewards entail.