In a perfect world, everyone produce something. Farmers grow plants, feed chickens, fishermen catch fish, builder made homes etc. So we can sit together at night and enjoy a complete dinner in our nice homes. It was easy to know who is suppose to do what, who produces what. When there are too many fish caught, it has to be sold out of town. The fisherman doesn't have time to travel that far. So a delivery boy is helping the fisherman. The fisherman save time, hence catch more fishes and therefore its worth him paying the delivery boy. It is a value added chain, so service has become a part of perfect world too where everyone produce something, everyone produce some values . It gets a bit complicated cause service is not as easy to quantify as materials. But its still ok. A $1 fish may cost $2 in out of town because there are delivery cost incurred. Soon more delivery services are needed. It is not easy to decide which of the 100 delivery boys is most reliable. So a mana...