I think 'Avengers' just rose the bar so high that it's really hard for films of the same genre to even compete without being seen as "not as good as 'The Avengers.'" I actually saw that happening the moment after the film ended. The world now knows whats possible and really won't settle for less. Any other summer Snow White & Prometheus & MIB 3 would have stuck out more I think.
Is The Avengers The Godfather or something? Is it sweeping the Oscars? It was just a perfect storm of multiple fanbases coming together, paying 3D ticket prices, great marketing, the appeal of seeing these characters that have been around for 50 years and lame competition.
The trailers for Dark Shadows, The Dictator, Battleship and MIB3 just didn't interest moviegoers.
Same thing happened last May but it was perhaps less dramatic or there was no great film at the beginning of May to trample those films.
Thor had a $65 million open because well that's what the marketing could drum up.
Pirates had a big opening but for the series it was a disappointing one and did poorly in North America compared to the other three.
Bridesmaids had excellent WOM (The Dictator not so much).
Kung Fu Panda 2 opened lower than expected and performed poorer.
The Hangover Part II made less than Part 1.
X-Men First Class didn't have the best opening against no new competition.
Super 8 opened small and there was the disaster that was Green Lantern.
Cars 2 was the lowest grossing Pixar film (after inflation).
Transformers Dark of Moon was also down, and was third in the series after inflation.
Harry Potter 8 did very well. Audiences wanted to see that and liked it.
Cowboys & Aliens bombed.
Rise of the Planet of Apes surprised people because they had low expectations and did better than Captain America and Thor at the worldwide box office. Who saw that happening?
The Help also had a great showing while Spy Kids and Conan sputtered out.
Great to good films that are marketed well, have great word of mouth will always succeed. Perhaps with the the recession people are less likely to gamble on films like they may have in years past (Green Lantern, X-Men, Cars 2) because of the higher 3D tickets costs or they don't mind waiting until DVD or even TV.
The only films I saw in theatres last year were:
Bridesmaids
The Hangover Part II
Harry Potter 8
Rise of the POTA
I've seen Thor, Captain America, Super 8, X-Men on Netflix and The Help on pay cable TV. While I rented Cowboys & Aliens and will get around to watching Transformers on Netflix.