A few months after Spider-Man's introduction, publisher Goodman reviewed the sales figures for that issue and was shocked to find it was one of the nascent Marvel's highest-selling comics. He has further commented that Ditko's costume design was key to the character's success; since the costume completely covers Spider-Man's body, people of all races could visualize themselves inside the costume and thus more easily identify with the character.

Writer Mark Evanier notes that Lee's reasoning that Kirby's character was too heroic seems unlikely—Kirby still drew the covers for Amazing Fantasy #15 and the first issue of The Amazing Spider-Man. Evanier also disputes Kirby's given reason that he was "too busy" to draw Spider-Man in addition to his other duties since Kirby was, said Evanier, "always busy".

Simon, in his 1990 autobiography, disputed Kirby's account, asserting that Black Magic was not a factor, and that he (Simon) devised the name "Spider-Man" (later changed to "The Silver Spider"), while Kirby outlined the character's story and powers. Simon later elaborated that his and Kirby's character conception became the basis for Simon's Archie Comics superhero the Fly.