It's a great example of selling a product. What is a Hard Rock Cafe t-shirt worth to anyone? Nothing at all. I used to see those t-shirts for years, every time someone went on vacation they brought one back. I finally went to one of those cafes and it's the most mind boggling thing. A sub par cafe, that's all it is. So why the shirts?
They are the pre-Apple. People buy the shirts because other people buy the shirts. The shirts themselves are worthless as artifacts.