How do agents and agencies typically get compensated for sponsorship deals?

Compensation structures vary but typically include: retainer-based payment (six months to one year) plus a percentage of every deal brought in. The lower the retainer, the higher the percentage; with no retainer, the percentage is even higher. These percentages don't decrease on renewals - agents continue to receive their percentage as long as the partners stay with the athlete, since the agent originally brought the deal. This protects agents from athletes who might try to cut them out after deals are secured. Athletes need to understand that if an agent brings funding they never had before, that agent deserves ongoing compensation for as long as those sponsor relationships continue.