There is a way that you can market a product or service for someone else and get paid if visitors buy it. It is called affiliate marketing and people can earn a lot from it. Unfortunately, it is not an exclusive domain. A lot of people are into the secret and competition can be fierce. A few tips on how to survive the game will help the new entrants.
One strategy is to jazz-up your content. If people enjoy what you are dishing out to them they will keep coming back. Once they come into your web, make every effort to keep them there. Offer them subscriptions to newsletters or provide a place where they can express their opinions. That way they are ever present in your list.