In the 1960s Marvel needed growth and innovation, DC wanted stability.
In the early 1960s, because Marvel and DC produced similar products many expected them to have had similar business plans. Nothing could be further from the truth. Marvel was a small company which had only one owner and one editor. Goodman was the publisher of several magazines and had a limited, but growing number of comics. DC was part of a conglomerate that produced comics, magazines and Signet paperback books. Its parent corporation included a distribution company and handled licensed properties such as James Bond.
With licensing now in the DC blood, its characters were used more to promote products from other companies. DC then seemed less innovative and they had much fewer in house ads. Marvel didn’t yet have those readily identifiable characters. Although it had been around for 2 decades, they acted more like a startup company.
Also, Stan Lee told us that he had learned from Bill Gaines and how he connected with the readers of Mad and other EC comics. Stan wanted to follow in his footsteps. So Marvel put out a ton of products including stationary, sweatshirts, pillows and coins. Yes, DC had Supermen of America, left over from the 1940s, but Marvel had Marvelmania and FOOM which were more in step with the children of the 1960s. And with their records Stan was able to add personal and show-business touches.