The idea is that Jason, some dude in the States, wears a different shirt each day of the year. He will then blog about, talk about it, link to your website and generally parade himself in the public eye in the name of your brand.
The first day is charged at $1, the last day sold $365. This works out to be a total earning of $66795 during the year, so it’s going to make him some fair cash – not as much as the Million Dollar Guy, but it’s entertaining nonetheless. Besides, he’ll probably clean up on the additional sponsorship.