A week after it opened in the US and UK, pundits are already calling Sin City: A Dame to Kill For a major box office flop. The last big blockbuster of the summer, the film scored $6 million at the American box office when everyone predicted it would earn at least $10 million.

Sin City 2 Dame to Kill ForGordon Joseph-Levitt in 'Sin City: A Dame to Kill For'

But there are a few things to consider: first, audiences are enjoying it, as demonstrated by its 72% positive IMDb rating. And second, it's still opening around the world. The film previewed in limited UK cinemas last weekend, but the receipts won't be added in until it opens wider this weekend, and its global total is at £13 million and counting.

Now comes the postmortem, as everyone tries to figure out what went wrong. Could it be the nine year gap since the Sin City's innovative visuals, during which everyone has stolen the idea and used it to death? Not to mention the fact that the predominantly male audience for the 2005 original has grown up now. They may be intrigued by the idea of scantily clad stars like Eva Green, Jessica Alba and Lady Gaga, but they're getting their kicks this summer from the all-green Zoe Saldana in Guardians of the Galaxy.

More: read our review of 'Sin City: A Dame To Kill For'

Of course, this isn't the first sequel to fail to live up to the hype. Just a week earlier The Expendables 3 fell far short of predictions. And last year, Kick-Ass 2 underperformed in the same August release week.

As everyone knows, no one in Hollywood has the secret of success. Films falter for a variety of reasons, from sunny weather to gloomy news headlines, both of which would affect a dark movie like Sin City 2.

Perhaps the real truth is that audiences are tired of sequels and cynical marketing ploys and are looking for something new. Although it seems unlikely that Hollywood will ever understand that.

Watch the trailer for Sin City: A Dame to Kill For