I recently watched a video of a solution-focus therapist working with a client. The clip began with a number of questions and statements with which the client would agree. In hypnosis and sales, it's known as a "yes set."
If you're not familiar with the concept, it works roughly like Simon Says. In that game, you get into a pattern of doing what "Simon says" so that you eventually do what the leader says even when s/he does not insert the magic words "Simon says." In the "yes set," you get used to saying yes until such a strong pattern of agreement exists that you agree with statements or instructions you might not otherwise give your agreement. The more times in a row you have said "yes," the greater the probability that you will say "yes" to the next statement.
Yes sets can be seen in two ways. The first is that you are offering someone evidence that you are observing and accepting their experience. When every statement or question elicits a "yes," it is because you have been feeding back your precise observation of what is already in the other person's experience. The therapist was using the "yes" set to build rapport by showing understanding. To do this accurately, you first have to put yourself into the shoes of the other person.
Yet it is also true that having someone say "yes" to you over and over again feels good to the person running the yes set and builds not only rapport but compliance. There is a fine line between building rapport for the sake of common ground and building rapport so that someone will go along with what you say or expect. This is especially true when the person running the "yes" set has more status or authority than the person saying "yes" - as in the case of a therapist who is "helping" a client.
The best "yes" sets are those where both people are taking turns saying "yes" and making statements. They indicate powerful shared ground and real collaboration. If you find that only one person is saying "yes" while the other makes statements or asks questions, be more cautious. The presupposition buried under all that agreement is that one person is providing direction and the other is going along with it. That's only healthy in small doses.