Martin Goodman began publishing pulp magazines in 1933, just as the earliest comics books were appearing. His company was nepotistic from the start, with his brother Abe Goodman in charge of accounting, his brother Dave Goodman doing photography, and his brother Artie Goodman in production. Martin's brother-in-law, Robbie Solomon, was the office gopher. In June of 1938, Superman first appeared in Action Comics, and comic book sales exploded. Martin, always quick to jump on a trend, launched Timely Comics the next year, which introduced such characters as The Human Torch, Sub-Mariner, and Captain America. In 1940, to assist in the extra work created by the new comic titles, a 17-year-old office assistant named Stanley Lieber was hired. He was the first cousin of Martin Goodman's wife. The very next year, the original editor left and Stanley took over the reins, doing a good enough job to keep the position permanently. When the comic industry went through a slump in the 1950s, Stanley at one point was the only staff member of the comic book branch, by that time rechristened Atlas Comics. Working with freelance artists and writers, Stanley became the main writer for the company, adopting the pseudonym of "Stan Lee." In 1961, the name of the comic line was changed once more, this time to Marvel Comics. Under that name, and in the space of only two or three years, Stan and artists like Jack Kirby and Steve Ditko created The Fantastic Four, Spider-Man, The X-Men, the Hulk, Daredevil, Iron Man, Thor, and a slew of other characters that reshaped the comic industry, made comic books attractive to older audiences, and launched sales to an all-time high. But the nepotism didn't end there. Stan brought in his brother Larry Lieber as a writer and artist for both comic books and the Spider-Man newspaper comic strip. Martin brought in his son Chip Goodman to help run the company, viewing him as his natural successor. But when Martin sold his publishing empire to Cadence Industries in 1968, Chip didn't stand a chance against the fame that Stan had created for himself as Marvel's cheerful and bombastic figurehead. So in this case, the nepotistic son lost out to the nepotistic cousin-in-law, but who could ever argue that Stan Lee was anywhere other than where he was meant to be?
[For more on this legend of American pop culture, read Excelsior! The Amazing Life of Stan Lee, by Stan Lee and George Mair, and Stan Lee and the Rise and Fall of the American Comic Book, by Jordan Raphael and Tom Spurgeon.]