|Thanks to The super hero satelite|
Back in the 70's this was sort of the way toys were marketed. You had a company produce not a line of toys but a single toy and market it. There were GI Joes which were a line of toys as were Star Wars, but most did not have the line of toys idea. You were buying some toy by some company back in those days. The might man and monster maker kit by Tomy or in this case Rom by Parker Brothers. They were tied in with comics so I guess that was the start of the cross pollination but nothing like the required cartoon / toy line you had in the 80's.
I am guessing this was easier on parents as you didn't have the villains and vehicles to buy, making it a one time purchase rather than constantly being hounded for more toys.
I have seen talk that Rom may be making a return, I am not sure about that he seems a bit out of touch for today's kids. In taking my daughter to Toys R Us yesterday I was amazed how different that place is from my memory. There are no models at all, those used to be a thing. Many of the toys I liked best were the True Legends I would have loved those as a kid, sad as those were the cheaper toys r us marketed toys. The Star Wars and Gi Joes did little to nothing for me.