The first rule of magazine covers is: Make ’em pay attention.

Stop them at the checkout stand, at the mailbox or while walking down the street. Does that image — the half-naked celebrity, the airbrushed model, the outrageous headline — turn heads? Does it make subscribers want to read and non-readers want to buy? Does it make them angry? If so, you’re on the right track.

Hard on the heels of Time magazine’s button-pushing cover of a young mother breastfeeding her nearly four-year-old son comes Newsweek’s rejoinder. This week’s issue has President Obama in a chin-up, hopey-changey portrait with a rainbow-colored halo above his head. The cover line: “The First Gay President”

No, Newsweek does not reveal that Obama is secretly gay. No one ever said a cover shot or headline has to have all that much to do with the story it’s promoting. Instead, the Newsweek cover is the come-on for an essay by journalist Andrew Sullivan that describes the political, legal and personal calculation that led Obama to declare his support for same-sex marriage last week.

An acceptable stretch, as these things go, but provocative all the same (and a play on a famed New Yorker magazine essay by Toni Morrison in 1998 that declared Bill Clinton “the first black president”). The Obama image immediately set off a blogosphere debate about how “controversial” the cover and cover line are (“It won’t be nearly as controversial” as Time’s breastfeeding cover, judged Yahoo News ever so scientifically).

Which is all very good, as these things go. Covers aren’t designed to be liked exactly; it’s much better to walk the line between thoughtful provocation and cancel-my-subscription outrageousness.

“You want people to engage and react” to them, says Michael Caruso, the editor in chief of Smithsonian magazine and a former colleague of Newsweek editor Tina Brown. “You want it to be talked about. You want to be at the center of controversy. That’s what Tina is fantastic at.”

Despite Time’s attempt to beat her at her own game last week, Brown is the acknowledged maestro of the holy-mackerel cover. As editor of Vanity Fair in 1991, she put a very pregnant and very naked Demi Moore in one of the most famous cover images ever. She then shook up the staid New Yorker magazine with more topical cover illustrations and images, including a Valentine’s Day cover in 1993 depicting an Orthodox Jewish man kissing a black woman, a reference to the racial tensions then besetting the Crown Heights section of Brooklyn.

Brown’s successor, David Remnick, continued her path, most pointedly with a satirical cartoon cover in 2008 that show candidate Barack Obama dressed in traditional Muslim clothing and Michelle Obama as a gun-toting militant giving each other a “terrorist fist bump.”

Last year, Brown sparked outrage with a Newsweek cover photo of then-Republican candidate Michele Bachmann appearing dazzled and somewhat crazed, and a Photoshopped image of the late Princess Diana walking side-by-side with her daughter-in-law-to-be, Kate Middleton. That cover prompted the Los Angeles Times to ask the eternal question: “Shocking, brilliant or just plain cheap?”

Let’s go with brilliant for a moment. A buzz-worthy cover can have a salutary effect on newsstand sales. Brown boosted the New Yorker’s by more than 100 percent during her tenure; Newsweek’s newsstand sales have increased 30 percent over the past year under Brown’s stewardship, the magazine says.

Controversial covers pay longer term dividends, too. Subscribers, says Caruso, “want to be surprised and entertained on a regular basis,” and memorable covers are an important first step come renewal time. By that measure, Brown has also made inroads: Newsweek subscription renewals are up 3 percent after six years of decline.

Besides, given the well-documented woes of all things printed, just about everyone has to play the cover game these days.

Caruso’s Smithsonian magazine — a wide-ranging and thoughtful journal like its namesake institution — last month featured a giant prehistoric snake bursting out of its cover. Harper’s magazine illustrated an article about humans and animals with a cover photo of a small jungle cat perched on the bare torso of a young female model. Even Foreign Policy — Foreign Policy! — featured cover skin: a naked model covered in black body paint done up to resemble a burqa.

The latter image was used to illustrate a “Sex Issue” cover essay by Egyptian American writer Mona Eltahawy about the suppression of women’s rights in the Middle East and the Arab world. But it was also an ironic comment about magazine covers, said FP editor in chief Susan Glasser. “It makes a point about their culture and ours, and about American magazines and sex,” she said. “I don’t think you can look at that image as anything other than a commentary on western culture’s obsession with the cliches of centerfolds and cover models and also the hard realities of the [Arab] culture that Mona is writing about.”

Yes, sex, or at least sexiness, sells. Eltahawy’s article has gotten more than a million page views, making it one of the most-read ever for Foreign Policy, which is owned by the Washington Post Co.

Like Newsweek’s gay Obama and Time’s breastfeeding mom, it also proves something about the “right” cover image: That in the age of iPads and Pinterest and all things digital, a magazine can still get people talking about it.