But more than the fear of spoilers leaking, Marvel must have been driven by the phenomenon of Black Panther. Not six weeks ago, box-office tracking suggested the film might be lucky to have an opening weekend take of $120 million, before doubling that over the four-day President’s Day weekend. While the month of March will offer enough competition from other studios to take T’Challa (Chadwick Boseman) off the top of the chart, Black Panther already represents a resounding creative and financial success.

Over the last two weeks, Black Panther has broken box-office records left and right; by the end of this weekend, it will likely have grossed around or above $500 million domestically, and it may well end up making more than The Avengers, the first big team-up with the Marvel superheroes. Marvel’s decision— presented as part of a Twitter thread with Robert Downey, Jr., but no doubt made a few days or weeks ago internally — may have been inspired by a few factors. But Black Panther’s dominant stance at the box office was probably the biggest of all.

This, in effect, is awfully similar to what happened with DC after Wonder Woman performed so well with audiences last summer. Justice League was an exceptionally messy film, but the new marketing foregrounded Diana Prince (Gal Gadot), shifting expectations to suggest that it might be more accurately titled Wonder Woman Plus A Few Other Heroes You Might Recognize. Though the Marvel Cinematic Universe is full of much more well liked heroes, don’t be surprised if the new Infinity War ads emphasize the presence of T’Challa, Shuri (Letitia Wright) and other Wakanda favorites.

Marvel is also helping push the goalposts of what constitutes the summer-movie season. Though that descriptor has long been elastic — last year alone, movies like Get Out, The Fate of the Furious, and Beauty and the Beast hit big at the box office opening in the early months of the year— placing Avengers: Infinity War in April just allows the studio, and Disney as a whole, to dominate the box office each month of the year. This shift means that Disney will have a major release in 9 of 12 months this year alone, leaving aside the massive dump of release dates they unveiled yesterday through 2023. Marvel’s choice to push Avengers: Infinity War is another way to emphasize to the rest of the competition that they’re unshakable, at least for now.

A couple weeks back, a story made the rounds detailing how close Sony came to owning the rights to what we now know as the Marvel Cinematic Universe. With hindsight, we can read this story and laugh at what seems like poor decision-making on the part of the Sony executives who thought owning characters like Iron Man and Black Panther was a waste of money. But 20 years ago, Marvel was far from a sure bet. Now, the tables have turned radically. Now, Marvel can achieve some of its biggest box-office success with a character who had never been as big of an all-audience favorite on the comic book pages as Spider-Man, and they can decide to shake up the release calendar as they like. If that larger calendar of releases is any hint, we can expect a lot more shake-ups in the future if that’s what Marvel and Disney want.