Had a newer agent handling what sounded like it was heading toward a genuinely upset customer, and instead of waiting for it to escalate into a complaint, I used the whisper feature to coach her through it live, telling her what to say next without the customer hearing a word of it. Call ended fine, customer had no idea a second person was even involved. Compare that to before, where I'd only find out something went badly after reading a bad review or getting a complaint forwarded to me days later. Review collected by and hosted on G2.com.
Whisper coaching only works if I happen to be watching that specific call at the right moment, there's no way to get alerted that a call's heading somewhere rough, so it's really just luck whether I catch it in time or not. Review collected by and hosted on G2.com.