Mark Cuban, billionaire and owner of the Dallas Mavericks has a free t-shirt business idea:

I was in NY for most of the week. Every time I walked past a newsstand or street vendor it disturbed me to no end that they wore their own clothing. In particularly, their own T-Shirts. Why?

Because it made absolutely no sense to me that some entrepreneur had not done a deal that required the employees of these businesses to wear branded T Shirts.

Dexter was everywhere in NY promoting the premiere of the show. Except on these T Shirts. How much would a hot dog vendor charge to wear a Dexter T Shirt ? A T Shirt promoting any product or brand ?