In most cases, the entry fee is heavily subsidized by the public since owners don't buy teams unless and until local government comes up with hundreds of millions of dollars. Leagues differ in how and how much revenue they share among members. Teams keep most home gate receipts and local broadcast money but share national broadcast money and revenues from official logos, gear, etc. The leagues also differ in how much revenue they get from each source. The licensees include companies like Reebok, Starter, Russell, Champion, Wilson, Logo Athletic and Nike.
Sales are billions per year and growing.
Cigarette and car companies are doing a similar gear thing. Corporate brand gear has entered the fashion world in a big way, especially among kids and young adults. Stars like Michael Jordan have helped to push sales. South Asian labor has helped to maximize profits. The new stadiums are designed specifically to facilitate retailing as the pro leagues move into other forms of business.