In professional sports, agents play a crucial role in managing athletes' careers and negotiating contracts. They typically earn their income through commissions, which are usually a percentage of their clients' earnings. These percentages can vary depending on the sport and the level of the athlete, but they generally range from 3% to 20%. Additionally, agents may receive bonuses for securing sponsorship deals or endorsements for their clients. It's important for athletes to understand how their agents are paid in order to make informed decisions about their representation and financial management.