(CNN)When Roger Federer made the decision to hang up his tennis racket last year at the age of 41, he did so as one of the most influential figures to have played the game.
Federer was dominant on the court, winning 20 grand slam singles titles between 2003 and 2018 and spending a total of 310 weeks at the top of the men's rankings during the course of his career.
Away from the court, the Swiss star proved eminently marketable, acquiring a lucrative sponsorship portfolio that made him one of the highest-paid athletes in the world. Even last year, when he didn't play a single ATP Tour event, he was estimated by Forbes to have made pre-tax gross earnings of $90.7 million.
Federer's marketability, specifically his long-standing sponsorship deal with sportswear giant Nike, is one aspect of the tennis star's life and career explored in a new book, "The Roger Federer Effect."
"Writing the book, we realized how enormous the impact Federer had, not just inside tennis, but outside it, too," Simon Cambers, the book's co-author, told CNN Sport's Amanda Davies last month.
In the below extract from "The Roger Federer Effect," Mike Nakajima, the former tennis director at Nike, explains what made Federer and Nike such a perfect match, saying that Nike could have done for Federer what it did for Michael Jordan.