Anecdotal evidence that at least some names can draw people in: the people sitting next to me at Ohio Star Ball during a pro-am session told me that they were not dancers and did not know anyone competing; they came to check out the hot guys from DWTS. This woman and her Mom had seen/taken pictures of or with Maksim Chmerkovskiy, and were more than a little disappointed that Tony Dovolani wasn't there this year. They had come the year before too. (We got to chatting because she asked to borrow my program, to plan her hot guy tracking strategy.)
Still, competing and judging are two very different things.