Robert Jackson sells luxury automobiles at a dealership in an upscale section of a major city. When he started out as a salesperson, he identified potential customers by visiting office buildings near the dealership and examining the directories in the buildings' lobbies. He discovered that there were several large law firms within a mile or two of the dealership. He would copy down the names of the law firms and their attorneys from the building directory. Then he would mail engraved invitations to each of the attorneys inviting them to the dealership to test drive a new car. Deciding to focus on attorneys exclusively, he purchased a directory of attorneys in the area and started expanding his potential customer base. Robert is engaged in