I could swear I read Instant Rapport earlier than 1990, but memory can be a tricky thing and that's the year it was published, so I must be wrong. I will state unequivocally that this is the book that taught me how to sell. I have absorbed mirroring/matching to the level that I don't even think about it; my husband used to tell me that he could tell who I was talking to on the phone just hearing my side of the conversation, because I was unconsciously mirroring the other person to the point that he recognized them through me. This is a must-read for anyone in sales but would also be extremely helpful for those who feel awkward in social situations and need a little help learning how to "connect." I hesitate to give a book like this 5 stars as though it were on the level of To Kill a Mockingbird, which it of course is not, but it has helped me in my own life to make connections, build rapport and become a better salesperson. It is a 5 star in the self-help genre because unlike most of the others, it not only delivers what is promised but exceeds it.