Most colleges and universities have a campus activity board that brings entertainers and special events to campuses. to locate and hire these entertainers, many campuses send their student activity board members to one of the seven regional conventions or the national association of campus activities (naca) convention. more than 100 entertainers, talent agencies, and companies that provide promotional services exhibit their products at these conventions in an area similar to a trade show. (conference attendees call this the marketplace.) approximately 20 entertainers are selected to present a short program (called a showcase) in which they demonstrate what they would do if hired to perform on campus. many other entertainers have videos and cds, which they hand out to student attendees. only one or two members of any student group can actually set up a contractual agreement with an entertainer or his or her agency. other student attendees provide input as to which entertainers best match the demographics of their institutions. refer to college entertainers. when some of the entertainers visit campuses, they give free t-shirts to people who came to see them perform. these tee-shirts are examples of: