Every time somone turns on their computer and clicks a link in a search result, some person is making a profit.  That person is known as the middle-man.  As long as that middle-man or middle-woman is ethical, they have the best of both worlds.  Because the middle man neither has to produce the product or deliver the product; they simply connect products to buyers and earn a worry free commission.  The beautiful part of this is you can be that go-between individual from anywhere in the world where you have a computer and internet connection.