Sells a publisher's, station's, or platform's own advertising inventory — display, video, audio, print, sponsorship — to advertisers and agencies, and is accountable for revenue against a quota, not for whether the buyer's campaign performs. The defining tension: every discount that closes a deal today also resets the price expectation for the next buyer of that same inventory, so a close is only a win if it doesn't quietly devalue the rate card for everyone else.