A Cheap Labor Force
The mass production of Cacao Beans probably started when the French and Spanish opened their first plantations. A plantation is a large operation on many acres of land that specializes in mass producing a valuable crop; in this case the Cocoa Bean. The Cacao tree only grows in tropical regions, which also tend to be third world countries. Ivory Coast, Ghana, Indonesia, Cameroon, Brazil and Ecuador produce the most Cocoa Beans of any country.
Due to the crippling poverty of these regions, often entire families will be dedicated to Cocoa Bean farming, even the children as well. The use of child slavery in the Cocoa trade has only recently come to the public light, the use of slaves in the chocolate industry has been well documented (and refuted by Cadbury, as an example) for over 200 years. Most people are unaware that slavery, and in particular, child slavery, is used to produce the majority of the chocolate we choose. The rampant use of child labor and trafficking first got attention in the early 2000's but it's taken many years for the atrocities to gain enough attention to be taken seriously. Chocolate is a $100 billion dollar industry, and many of the major Chocolate manufacturers have admitted fault, but still use child slavery for acquiring Cocoa Beans.