"It's a modern-type of wholesome. We're living in a very different world now. Sarah Palin's daughter has a child out of wedlock," said Fuller, the editor in chief of Hollywood Life, a celebrity and entertainment website. "Despite everything that has gone on with them, they come across as a very tight-knit family, and that appeals to women."
Any conversation about the Kardashians' popularity eventually touches on the sexual allure of Kim. The tape she made with rapper Ray J -- she initially sued to stop it but later reached a settlement with distributor Vivid -- is "definitely a best-seller," a company spokeswoman said while declining to provide sales numbers. There was also a Playboy pictorial and her annual pin-up calendar. But she has managed to pull what marketers say is an unusual feat -- appealing to men without pushing away women.
"She's attractive to guys because she's absolutely beautiful," said Brad Haley, the executive vice president of marketing for CKE Restaurants, whose Carl's Jr. burger chain hired Kim to promote its new chicken salad. But she also draws in women, he said, because "she's not a waif-thin model. She's got curves . . . and talks about how she's got to diet and keep after her body."
"[Our fan base] started off very male, but it's transformed into a very heavily female base," Kim Kardashian said Tuesday backstage at the New York runway debut of a new Kardashian fashion line from Bebe. "I think that's because we're not afraid to share our beauty secrets and our flaws. If I have cellulite, I'm not afraid to talk about it and try to find a product to make it look better."
Beyond "Keeping Up" -- which Kris Jenner calls "the mothership" -- and its spinoff, the Kardashians stoke their tech savvy fans with an intense online presence. Kim's website, where she blogs and posts answers to fan questions, gets more than 6.7 million page views a month, according to Quantcast. Khloe's gets 3 million and Kourtney's 2 million, according to site operators.
"They have embraced social media in a way that is profoundly different than other celebrities," said Karina Kogan, chief marketing officer for Buzzmedia, a company that operates celebrity sites, including the Kardashians'. While Britney Spears, another Buzzmedia partner, relies on "a team of folks" to write the material on her site, the Kardashians most often handle it themselves, she said. The sisters routinely make news on Twitter or their blogs. When Kim wanted to refute reports that she had breast implants, she posted a photo of herself in a bikini at age 14.
How long the Kardashian franchise will endure is a subject that sparks debate. Kim's appearance on "Dancing With the Stars," which could have established her legitimacy as an entertainer with a broader national audience, fizzled when she was sent packing after two episodes.
"It remains to be seen how [the Kardashians] will do in the future. I don't think the TV show has an incredibly long shelf life," said Delzell, the branding executive.
But Kris Jenner is convinced otherwise. Asked to look 10 years in the future, she doesn't hesitate.
"It's 'Keeping Up With the Kardashians,' season 24. Kylie gets married," she said.
Times staff writer Greg Braxton contributed to this report.