The Insider.com

Though she broke countless records last year with her critically acclaimed album 21, turns out there's one thing that Adele can't sell -- magazine covers.

• May 18, 2012Jared Talks First Time Fatherhood
• May 17, 201250 Cent in Hospital with Stuffed Animals
• May 17, 2012Say What? Joey Lawrence, Chippendales Stripper
• May 17, 2012Meet Michelle Phan, The Accidental Millionaire
• May 16, 2012Linda Hogan on Being 'Addicted' to Young BF
• May 16, 2012One-on-One with YouTube Sensation 'Fred'

Adele's British Vogue cover turned out to be one of the magazine's worst sellers ever.

Related: Five Things You Don't Know About Adele

"Adele is the most popular woman in the world, but one of the worst sellers we've ever had," editor Alexandra Shulman surprisingly revealed at the "ToMax talk Fashion and Fantasy: What's in Vogue and Why Does It Matter?" event in London last night. "I find there has to be a relationship with the person on the cover that goes beyond how they look."

While that would certainly explain why the always unrelatable Gwyneth Paltrow's magazine covers usually bomb, it doesn't make sense when it come to Adele. Didn't 21 sell so well precisely because people did care about her personal heartbreak?

Related: Adele vs. Lea Michele

But perhaps it's just musicians in general who are unappealing to glossy readers.

"Music stars haven't sold at all well," Shulman added.