Marvel Studios is in a strange position in that it not only competes with rival DC, but also with itself to some extent. With several of its key properties owned by Sony and Fox, the studio's chief Kevin Feige often shows little interest or desire to help the properties they don't fully own (and thus don't make as much money on).
One example is Fox's "X-Men: Days of Future Past". Despite Marvel's complete lack of involvement in the film, the movie has become not just one of the biggest box-office hits of the year ($744.6 million worldwide) but also one of the most well-regarded wide releases so far in 2014.
That's a reaction even Feige is impressed by, and in a recent interview with Empire he reluctantly gives the film credit for returning the franchise to prominence:
"I've been thinking about Days of Future Past a lot, which I had nothing to do with, in terms of the resurrection of a franchise. I think they did a very good job with that."
In the same interview, Feige also touched upon the topic of 'threequels' and what they considered when they made their first one ("Iron Man 3"):
"On Iron Man 3, I thought a lot about X-Men: The Last Stand and Spider-Man 3 and I thought a lot about Toy Story 3, and how to avoid falling into threequelitis, which is why we went down a lot of the roads we went down on that movie."
The quotes come as Marvel seemingly backs away from another of its property - this time Disney Animation's "Big Hero 6" film this Thanksgiving. Not only is Marvel Comics not publishing any reprints or new material to tie-in with the film, but the characters aren’t scheduled to make appearances in any other Marvel comic titles in the foreseeable future, either. In fact their last appearance in comic form was in 2012.
Source: Heat Vision