Thirteen years before “Dear John” opened to $32.6 million, the New York Times concluded that women had suddenly become a powerful force at the box office. The male studio executives responded as only male studio executives knew how.

“The aim is to do action films that are more women-friendly, that is, having strong women in top roles and taking out a lot of the violence,” chimed then-Fox chairman Bill Mechanic, specifically noting the inclusion of Sandra Bullock in the “Speed” franchise.

While women were merely being invited onto Bullock’s blockbuster bus back in those days, they seem to be driving it now. And not just as male-action-hero stand-ins.

Indeed, the lightly regarded chick flick seems to have given way to a new box-office force: the female-driven tentpole.

Sony/Screen Gems’ “Dear John," which drew an audience last weekend that was 84 percent female -- and 64 percent below age 25 -- is but one example of a major box-office hit fueled almost entirely by women.

The female-driven movie isn’t a new phenomenon. But going back to mid-November -- and also factoring in Summit’s mega-hit “Twilight Saga: New Moon” (which opened to an audience that was 80 percent female) and Warner’s older skewing “The Blind Side” (60 percent female) -- every No. 1 film at the domestic box office not called “Avatar” has been chick movie.

Also performing strongly: Universal’s Nancy Meyers rom-com “It’s Complicated,” which grossed $176 million worldwide under “Avatar’s” shadow.

Meanwhile, Paramount’s Peter Jackson film “The Lovely Bones” was dead in the water until the studio figured out how to recast its marketing toward young women. Finally opening wide in early January to an audience that was 72 percent female and 40 percent under the age of 20, the $65 million film now at least has a remote shot at recouping its $65 million production budget.

In fact, “New Moon” and “Blind Side” only closed out what was an estrogen-fueled year at the box office, with stars like Sandra Bullock and Meryl Streep outperforming their A-list male counterparts [1] in terms of theatrical revenue.

And from Disney’s “The Proposal” (with an audience that was 63 percent female) to Sony’s “Julie and Julia” (67 percent women), studios didn’t just release successful movies with a narrow audience-composition edge favoring women, like, say, “Titanic."

These were hits driven almost entirely by female audience members.

And it's not that there is some big new trend of more women going to the movies. Rather, said Vinny Bruzzese, executive vice president of the motion-picture group for research firm OTX, the over-performance among women for certain films shows that “studios are catching on that you have to make the movie for someone. Movies that are for a specific audience tend to overperform.”

Martha Lauzen, executive director of the Center for the Study of Women in Television and Film at San Diego State University, concurred. “Women are just as likely to go to the movies as men,” she told CNN, right after the huge premiere of “The Blind Side.” Instead, she noted, studios are making more movies now that accurately reflect women’s experiences and interests.

And the studios executives are often more surpised than anyone with the results.

In 2004, New Line adapted Nicholas Sparks’ best-seller “The Notebook” into a sleeper hit that opened to $13.5 million.

The next Sparks adaptation, “Dear John,” outperformed the most optimistic pre-release estimates by over $7 million last weekend -- more than doubling “The Notebook’s” opening in the process. “It’s hard to wrap your head around this, because it’s never happened before,” Sony distribution president Rory Bruer told TheWrap.

Of course, narrowly targeting the female audience quadrants doesn’t guarantee success. In mid-January, Universal tried to counter-program a box office full of male-driven hits (“Avatar” specifically) with the Amy Adams-led romantic comedy “Leap Year.” The film made only $25.4 million. Likewise, Disney endured similarly middling results ($21.3 million) with the Kristen Bell rom-com “When in Rome” two weeks later.

But these were hardly costly misfires -- “Leap Year,” for example, costs only $19 million to make. And on the upside, Relativity Media said it paid only $25 million to fully finance “Dear John.”

In fact, grossing $704.7 million worldwide on a production budget of just $50 million, “Twilight Saga: New Moon’s” profitability actually surpassed the two male-driven tentpoles that ranked ahead of it in 2009, “Harry Potter and the Half-Blood Prince”($934 million in global box office on a production budget of $250 million) and “Transformers: Revenge of the Fallen” ($836.3 million/$200 million).

Certainly, with Summit ready to debut the next “Twilight” this spring, as well as another Robert Pattinson drama, “Remember Me,” on March 12, the female-driven tentpole might become even more ubiquitous in 2010. This isn't even accounting for Warner's upcoming follow-up to "Sex and the City," which grossed $415.3 million on a production budget of just $65 million two years ago.

“It’s getting all those young girls Tweeting and telling their friends how good the movie is,” noted Relativity marketing chief Geoffrey Ammer, following “Dear John’s” big score over the weekend. “That’s the key.”