I ordered something on Amazon a while back and was given a 3 month free trial of their Prime membership. It something like $80 a year. With it you get, I think, free two day shipping and discounted next day shipping. It was free to try so I went for it. My 3 months is about up and I am going to cancel it.
Because I think I would feel like I needed to buy stuff to get my money's worth. And that would be kind of counter productive.