Doubt the Oprah Effect? Here are some of the ways Ms. O has worked her magic:
• After her first Tweet on April 17, and a subsequent show featuring Ashton Kutcher as the first million-follower user, signups for Twitter.com jumped massively (estimates range up to 1 million), and she attracted more than 300,000 followers in a day, according to the Washington Post.
• Economists at the University of Maryland found in a study last year that Oprah's endorsement of Barack Obama brought him 1 million votes. According to Political Wire, the study linked subscriptions to Oprah's magazine, O, and participation in her book club to increased voter participation.
• In 2007, Oprah's endorsement of two diet books sent their popularity soaring, according to the Nielsen BuzzMetrics service at the time. The two, You on a Diet and The Best Life Diet, got considerable buzz and a huge bump in sales after she endorsed them. (Never mind her own continuing struggles with the topic.)
• Speaking of book endorsements, when her book club began in 1996, it proved an immediate launching pad for authors, who saw their sales take off. The club also proved lucrative for dead authors. The New York Times reported in 2005 that her book club helped boost sales of three William Faulkner novels (As I Lay Dying, Light in August, and The Sound and the Fury) from 140,000 a year to 900,000.
• Products ranging from Adam + Eve cotton T-shirts to a mini portable diaper changing station to MarieBelle hot chocolate powder saw their sales sometimes double or triple and their businesses take off after mentions on the show or in O, the magazine, according to BusinessWeek, which surveyed 11 companies who earned an Oprah shout-out.
Compiled by Anne Glover, Times staff writer