Before David Maisel arrived, deals were being done to sell Captain America and Thor to Warner Bros and Sony respectively.
After almost 10 years and 13 films, Marvel has more than proved the merits of their groundbreaking shared movie universe technique.
In the article, Maisel talks about how Marvel almost sold the rights to Captain America and Thor, which would have ruined the idea for a film universe.
Marvel used to license their characters to outside studios, and it seems that they almost sold key members of The Avengers:Thorand Captain America.