Looks like they're putting in place infrastructure for an API affiliate plan.

To use the API you must display a copyright link whose href points at a url included in the API's response.

Ignoring the nice boost this gives to Google rank, the urls change based on the request and so can point to a place where the viewer can buy the API response's content from Marvel.

Plus each url includes a tag so Marvel can know which app sent them the customer.

Not sure why they're putting such a powerful linkback/affiliate scheme in the copyright notice though. If they're sending back custom urls it's no extra effort to include call to action text for the link as well eg: Buy 'Avengers: The Quest For Profit'.

More info in the linking section of http://developer.marvel.com/documentation/attribution