Theatre critic Martin Kohn writes about the successful efforts of a theatre marketing class at Wayne State . Graduate students in the class are conducting the season ticket subscription campaign for the university's theatres. Sixty percent of each student's final grade depends on how many subscribers they attract. Professor Anthony Rhine, who heads the MFA program in theatre management, believes subscriptions will be up about 15 percent this year. He says the real purpose of the class is to help students "learn about the process." Kohn also interviewed two students in the class, who talked about what they gained from the marketing experience as well as their future plans. An insert notes that the 2006-07 season open house at the Hilberry Theatre will be from 1-4 p.m. Saturday.