marvel can link up with a gym shoe company- nike, adidas, reebok, converse, etc.,

and come out with some gym shoes based on their characters- limited editions aren't far-fetched, especially nowadays, i.e. nike air force ones, they could be cool collectibles, as well as to wear--

spider-man
captain america
iron man
hulk
wolverine/x-men
black panther
moon knight
daredevil
thor