Oprah Winfrey has announced that she will extend her partnership with WW International Inc (WW  ), formerly Weight Watchers, through May 2025.

As an adviser and major shareholder, Oprah currently has 8% stake in the company. She started with 10% stake which she bought for $43 million.

Since Oprah joined in 2015, shares of the weight-loss company have gone up 500%. Within the first year, membership had grown to 2.8 million, and by the beginning of 2017, Weight Watchers membership was up to 3.6 million.

Since typically whatever Oprah touches seems to turn to gold, those growth figures don't come as a complete surprise. Consider the successes of Dr. Phil and Dr. Oz, consider Oprah's Book Club. Her endorsements tend to amount in a more-than-significant boost in brand awareness and subsequent major increase in sales for the endorsed individual or product, which has been termed "The Oprah Effect."

Weight Watchers seems to be waning these days, however. That's especially true considering other more popular weight-loss brands and fads that have come on the scene, such as the keto diet. And Oprah's continued partnership may not be able to change that reality this time around, despite the announcement of her 2020 tour, Oprah's 2020 Vision: Your Life in Focus, with WW as Oprah's "tour partner."

Still, Oprah remains committed to maintaining her endorsement, at least for now.

"I am passionate about WW's potential to reach and inspire even more people in the years to come," Oprah said. "I believe in WW's mission and the power of its program to create positive, lasting change for everyone who wants a partner to help support them in pursuing a stronger, healthier life."

Oprah's executive positions include Chairwoman and CEO of Harpo Productions, Inc., a subsidiary of the privately held Harpo, Inc., and Chairwoman, CEO, and CCO of the Oprah Winfrey Network (OWN), the majority owner of which is Discovery Communications Inc. (DISCA  ).