What do Spanx, panini-presses, Uggs, and Kyocera knives have in common? If you answered with "items my Mother loves" you're not that far off. Why have said items made their way into every American family's gift-giving for the past decade? Look no further than the Queen of Daytime — and her Favorite Things.

With over 40 million viewers in 150+ countries tuning into Oprah every afternoon, you can imagine the impact that Oprah's signature "seal of approval" can have on an item. Take a look at any one of her hundreds of Favorite Things since she launched the annual segment in 2002, and you will notice a huge spike in profits that directly corresponds with the year the brand was featured.

Upon being listed as a Favorite Thing 2010, Kyocera knives sold 740% more than they had the year before. When Fat Witch Brownies were featured in 2002, it took the small bakery over six months to respond to the orders out that had been placed up on the viewing. When local NYC beauty store Carol's Daughter was featured, their website went from around 4 people visiting per day to 17,000 visitors — and subsequently, crashing their website. The good news? The business went from a $2 million net worth to $30 million today.

But the Oprah Effect is hardly limited to her Favorite Things. Yes, we're talking about the Book Club. USA Today reports that the "Oprah editions" of the 70 titles in her book club have sold over 55 million copies, helping to revitalize the struggling publishing world. No need to worry about the Book Club post-Oprah Winfrey Show: she's planning a new show for OWN that will feature all over her favorite books. And why not? What's to stop her from creating a show entirely about her "Favorite Things" as well? Surely, her highly-coveted seal of approval will live on beyond her daytime talk show — but will "The Oprah Effect" still have an impact when it's not being broadcasted on network TV?

Oprah Winfrey's Favorite Things Feature Gave Businesswomen Big Boost [GMA]
How the 'Oprah Effect' changed publishing [USA Today]