moremore has the details. >> reporter: one of the biggest names in weight loss. >> how does it feel to lose weight while on weight watchers? >> reporter: gaining a powerful new partner. weight watchers announcing oprah winfrey has bought 10% of coming on as a "board member a and visor and celebrity face. the media mogul tweetiting, "i believe in the weight watchers program so much i decided to invest." that investment sending the slumping stock soaring. oprah herself making approximatately $70 llion today. the partnership reflects weight tchers efforts to broaden the company's mission to prioritize overall health and wellness. winfrey, who has famously struggled with her weight over the years -- >> it is amazing to me that i can't lift it, but i used to carry it around every day. is a marketing force. the oprah effect seen with books, her favorite things, and now on the stock market. winfrey will also join weight watchers as a member, sharing her own personal experiences with the program. mara schiavocampo it, abc news, new york. >>> i can't wait to hear her personal experiences. she i