When it comes to book sales, Arianna is no Oprah

Arianna Huffington and Oprah Winfrey have a lot in common: They're both on TV a lot, they both love Barack Obama, they're both full of advice for how you should live your life, they both endorse dubious medical theories, and so on. And, as of this week, they both have book clubs. But does Huffington have Winfrey's magic touch?

Much has been written about "the Oprah Effect": Winfrey's uncanny ability to turn just about any book (or other product) she recommends into an instant best-seller. I tracked the Amazon.com sales rankings of In Praise of Slowness by Carl Honore, the inaugural selection of "Arianna's Reading," Huffpo's new book club, to see if there's an Arianna Effect.