Each year, the supply of specie in the colonies decreased due to international factors. The dearth of specie rendered it ineffective as a means of exchange for day-to-day purchases. Colonists frequently adopted a barter system to acquire the goods and services they required. Essentially, this method proved to be ineffective and a commodity system was adopted in its place. Tobacco was used as a monetary substitute in Virginia as early as 1619. A major shortcoming of this system was that the quality of the substitutes was inconsistent. The poorer qualities ended up in circulation while the finer qualities were inevitably exported. This commodity system became increasingly ineffective as colonial debts increased.