The ultimate aim of the Mafia is to earn money. They achieve this objective by taking part in many illegal enterprises. One of the earliest and most common method which is also the simplest is extortion. Extortion is taking someone's cash forcefully by threatening him or her. The Mafia may tell a shopkeeper to give them $ 100 every week because the Mafia wishes to give them "protection" from some "criminals" who wish to harm their family and demolish their shop. The implication is that the Mafia itself is the criminal. This is a type of extortion. Most people agreed to pay. The one's who did not have to deal with serious repercussions. Their shops were torn and they were often sent "sleeping with the fishes" (ie drowned) or "filled with lead" (ie shot indiscriminately and stuffed full with bullets) but generally such drastic measures were not required cause the reputation of the Mafia spoke for itself.
The Mafia makes money by participating in virtually every illegal activity. Illegal goods are generally expensive, untaxed and unregulated by the government. Over the years, the Mafia have deal in alcohol during prohibition, illegal drugs like cocaine and heroin, prostitution and illegal gambling. They even had some legal ventures like hotels and casinos.
Sometimes burglaries, muggings and robbery were used for getting income. But most of the Capos were very ambitious and knew that they needed grander schemes for learning more cash. Due to this reason, the Mafia often hijacked entire shipment of trucks and unloaded a large amount of stolen goods in warehouses. The stolen goods could have anything from television sets to clothes to jewelery. Another effective method of the Mafia was to pay off the truck-drivers and dock workers who would "misplace" the crates of goods which ultimately reached the Mafia's hands.
One of the most infamous schemes of the Mafia was the infiltration of Labor Unions. For several decades, every major construction project in New York City was controlled by the Mafia through the Labor Unions. The Mafia paid-off or threatened union leaders in order to obtain a piece of the action whenever they got a construction project. Sometimes they even took over the rank of leadership themselves. Once the Mafia had its grip on a Union, it could control an entire industry. The Mafia could halt or slow down a project if contractors and developers did not make the right pay-offs to the Mafia. The Mafia even had access to huge Union pension funds. During their peak time, the Mafia could have bought almost all construction and shipping in the United States to a halt.