Negotiatores, Mercatores and Pedlars
The Romans knew two types of businessmen, the negotiatores and the mercatores. The negotiatores were in part bankers because they lent money on interest. They also bought and sold staples in bulk or did commerce in wholesale quantities of goods. In some instances the argentarii are considered as a subset of the negotiatores and in others as a group apart. The argentarii acted as agents in public or private auctions, kept deposits of money for individuals, cashed cheques (prescriptio) and served as moneychangers. They kept strict books, or tabulae, which were considered as legal proof by the courts. The argentarii sometimes did the same kind of work as the mensarii, who were public bankers appointed by the state. The mercatores were usually plebeians or freedmen. They were present in all the open-air markets or covered shops, manning stalls or hawking goods by the side of the road. They were also present near Roman military camps during campaigns, where they sold food and clothing to the soldiers and paid cash for any booty coming from military activities.
There is some information on the economy of Roman Palestine from Jewish sources of around the 3rd century AD. Itinerant pedlars (rochel) took spices and perfumes to the rural population. This suggests that the economic benefits of the Empire did reach, at least, the upper levels of the peasantry.
Read more about this topic: Roman Commerce