What is the Killer Compliment? It is commenting on some very personal and specific quality you spot in someone. A Killer Compliment is not "I like your tie" or "You're a very nice person." (The first is not personal enough and the second is not specific enough.) A Killer Compliment is more like "What exquisite eyes you have," (very specific) or "You have a wonderful air of honesty about you," (very personal).