This image was lost some time after publication.

We assumed in last week's Defamer Attractions column that $75 million opening-weekend estimates seemed awfully conservative for Iron Man, but even our $90 million forecast undershot the film's $100.7 million three-day take. (It was $104.2 million if you count Thursday night previews, and more than $200 million globally.) Aside from the obligatory splash for any early-summer tentpole, we're surprised observers didn't see the finely calibrated alchemy that Marvel and Paramount used to spin its Iron into box office gold:

1. The Schlub Factor. Like Sam Raimi, who guided Marvel's previous blockbuster franchise Spider-Man to its own record openings in 2001, 2004 and 2007, director Jon Favreau is kind of a schlub — a normal dude who came up through the ranks and pretty much is his audience. He's not Ang Lee, whose misunderstood Hulk is disavowed to the point that its own studio is remaking it this summer (with another non-schlub, French action auteur Louis Leterrier), or even Bryan Singer, whose X-Men franchise coasted on star power before burning itself out at the hands of patronizer extraordinaire Brett Ratner. Favreau imposes a fan's vision and an indie mandate (i.e. character development, budget-mindedness) that works primarily because it threatens no one — neither the studio that paid for it nor the viewers spreading word-of-mouth months in advance and lining up around the block on opening weekend.

2. The Downey Factor. Repeat everything above, but substitute Tobey Maguire and Eric Bana (the miscast Hulk whose 2008 replacement, the relatively inaccessible Edward Norton, will likely suffer a similar fate). Robert Downey Jr. is a smart, funny adult actor who appeals to men and women alike (especially women), while also an innocuous enough leading man who won't overshadow the brand among fanboys. He's also his generation's most powerful Hollywood comeback story; this guy was virtually uninsurable after his umpteenth drug bust six years ago cost him his role on Ally McBeal. His casting was about as brilliant as it gets.

3. The McDreamy Factor. Or: There was nothing else to see over the weekend. Sony says it's happy having done $15 million with Made of Honor, but it thought its Patrick Dempsey rom-com would pull in at least $6 or $7 million of what went to Iron Man — on the basis of counterprogramming alone. What it didn't count on was...

4. The Female Factor. Iron Man was more of a chick flick than most "experts" anticipated, which Variety noting today that women made up 38% of last weekend's audience. Again, Marvel can thank Downey, but it shouldn't forget leading lady Gwyneth Paltrow. Her presence likely accounts for at least $12 to $15 million of that opening windfall.

5. The Critic Factor. The film was arguably critic-proof, but no one can deny the taste- (and profit-) making influence of reviewers who pushed Iron Man to a 94% positive rating at Rotten Tomatoes. That is the stuff of franchise phenomena — Iron Man 2, here we come.