Couriers have been a part of the advancement of world markets for centuries. The ability to transport anything from point A to point B has been a necesity since the beginning of trade. As a matter of fact, that is exactly how Wells Fargo and the U.S. Postal service started out.
Large delivery companies simply cannot provide the level of personal responsibility and timeliness that a "man with a van" can. The moment you confirm payment your package will be picked up and taken directly to your delivery location.
Couriers are usually competitively priced for local deliveries. Depending on the size of the vehicle used and the distance and urgency of the delivery, the price will be more pricey compared to a service that may take 24 hours to deliver a package.