Competently setting up an Agenda & Expectations / Up Front Contract is one of the major tools for advancing the sales process. Without spending the time to do so, you will continue to be the victim of unexpected changes in your prospect's schedule. Also, you and your prospect will both proceed believing you understand the other's mind; however, this will almost never be the case and will result in "collective confusion" or "mutual mystification."
Notes from the presentation are below.