BARBENHEIMER: THE STORY BEHIND THE SUMMER'S MOST ONLINE MOVIE SHOWDOWN

The very online showdown between Greta Gerwig’s “Barbie” and Christopher Nolan’s “Oppenheimer” all started with a date: July 21.

It’s not uncommon for studios to counterprogram films in different genres on a big weekend, but the stark differences between an intense, serious-minded picture about the man who oversaw the development of the atomic bomb and a lighthearted, candy-colored anthropomorphizing of a childhood doll quickly became the stuff of viral fodder.

There’s even some disagreement over whether it’s “Barbieheimer” or “Barbenheimer” or “Boppenheimer” or yet another tortured portmanteau — a phenomenon on which the AP Stylebook has yet to offer guidance, but for the purposes of this article will be “Barbenheimer.”

It didn’t hurt that both Nolan and Gerwig have very passionate and very online fandoms eager to join in. Never mind that many of those fans overlap — the memes, allegiances, and T-shirts were just too fun.

Both movies often trend on social media when the other releases a new asset — a trailer, a picture, an interview. On one level, it’s a marketing department’s dream. Awareness could not be higher, the conversation couldn’t be louder, and neither film even has official reviews out yet.

“’Barbenheimer’ is a marketing gift borne out of social media and I think it’s benefiting both films,” said Paul Dergarabedian, the senior media analyst for analytics firm Comscore. “You’re certainly aware of both movies in a more profound and compelling way than I think might have otherwise happened had they been released on different weekends.”