The Avengers raked in more than $200 million in U.S. box office, making it the biggest three-day domestic opening of all time. But there's one metric where the Joss Whedon-directed superhero blockbuster actually underperformed: piracy. As hard as it is to believe, the film was only the third-most downloaded movie on BitTorrent last week, despite being on the market for more than a week overseas.

Yes, despite efforts by Disney and Marvel to prevent copies of the film from circulating online, cam rips of The Avengers are definitely being traded online. Nevertheless, the popular new film was less downloaded than Haywire, the Steven Soderbergh action film that came out months ago and was just released on DVD. Both films ranked behind the McG-directed This Means War, according to figures from TorrentFreak.

PHOTOS: 28 of Summer's Most Anticipated Movies

So what does this mean? Have studios successfully mitigated the piracy threat?

Judging by what we saw at the premiere of The Avengers, Marvel/Disney were very careful about controlling leaks, going through bags like TSA agents at an airport. Some studios and theater companies are experimenting with new technologies like sending out a beam of light onto unsuspecting movie watchers to uncover those camcording. Police have even arrested individuals recording The Avengers on their mobile phones.

These efforts still don't explain why a geek phenomenon like The Avengers ranked just third on TorrentFreak's top most pirated films last week. Cam rips of The Avengers were available online, and regardless of how tough they were to find, pirates have proved resilient to countermeasures on popular films in the past.

A Disney spokesperson didn't respond to our requests to explain why the film wasn't more consumed on pirate channels.

VIDEO: Behind the Scenes of Marvel's 'The Avengers'

On message boards like TF's, observers are pointing to The Avenger's failure to grab the top spot as evidence that fears about piracy destroying theater attendance have been overblown. Others seem to suggest the low quality of the cam rips is a factor in keeping the numbers down. That might change when better versions become available, potentially cannibalizing sales off of DVDs and on distribution channels like iTunes.

In the meantime, the news represents a positive not only for Disney but also to theater owners.

Benjamin Mogil, an analyst at Stifel Financial, notes that of the 20 highest-grossing screens in America, 17 were Imax. "If there was ever a sales pitch to add an Imax screen, that was probably it," he says.

Another interesting statistic: More than half of the theatrical box office (52 percent) last week was generated by non-Imax 3D, though this probably has more to do with the overwhelming success of The Avengers than the false notion that 3D is immune to piracy.

Over at the website Plagiarism Today, Jonathan Bailey has his own nuanced take about how to square the fact that piracy hasn't destroyed the box-office popularity of The Avengers. He writes, "Saying that 'The Avengers did well, therefore piracy is not an issue,' is akin to saying, 'It’s cold today, therefore there’s no global warming.' It’s looking at a small, narrow sample and trying to extrapolate results that are far too big."

E-mail: eriq.gardner@thr.com

Twitter: @eriqgardner