I don't use a tanning bed, but I did when I was in high school, and I always saw a black girl there that was a classmate of mine. Despite being African American, she had light skin and wanted a tan. I definitely would think a greater number of whites use the beds, though.
I went to the tanning bed for my mild psoriasis per my doc's recommendation (clears it right up!). I used sunscreen while in the bed. I think it is very unfair to tax tanning bed usage when it is used as light therapy for the treatment of a skin disease.