With all due respect, what you suggest (build rapport; think like your customer) are 2 (and only the tip of the iceberg) methods Dale Carnegie Sales Training teaches/covers.
Keep in mind, there is a huge difference between the Dale Carnegie Communications values, and its Sales Training courses. The sales training, while based on the communications principles, are more about understanding your customer, and the value of what you're selling to your customer from THEIR point of view.
Gone are the days of "Be nice and people will like you and therefore buy from you" Instead, it's like you wrote... think like your customer.
Just for the record, I have absolutely no interest in, or gain in any way from others using the DC method. I just know how much it did for me and my sales practices.