"The power of Winfrey's political endorsement is unclear. But she has a track record of turning unknown authors into blockbuster best-sellers when she mentions their books on her program. For Oprah, the campaign swing provided a much-welcomed respite from some controversies that put her back in the news recently."

--some example on the biography about Oprah Winfrey at biography.com--

this is the link to my friendster... hehe...