Kylie Jenner just taught Snapchat an important--and expensive--lesson about why businesses need to listen to their customers.

The 20-year-old social media maven and entrepreneur tweeted on Wednesday that she doesn't use Snapchat anymore and the next day, shares of Snap dropped 6.1 percent, wiping $1.3 billion of the company's market value. By Friday morning, her statement had been retweeted more than 61,000 times and liked by more than 319,000 users. 

Jenner, who is a member of the Kardashian-Jenner family and runs her eponymous cosmetics company, has 24.5 million followers on Twitter. While she quickly issued another tweet expressing her love for the company, her opinions echoed a similar dissatisfaction other Snapchat users voiced after the app's recent redesign.

About 1.23 million people have signed a petition on asking Snapchat to remove the update, saying that the redesign made the app harder to use. As the one-month-old petition neared its goal of 1.5 million signatures, Snap responded and encouraged users to stick with the app and learn its technology.

Snap CEO Evan Spiegel had similar remarks at the Goldman Sachs Internet & Technology Conference in mid-February. "The tech is an important piece but I think the harder part you can't get around is the time it takes to learn," he said. "It'll take time for people to adjust, but for me using it for a couple months I feel way more attached to the service."

Snap went public nearly a year ago but has failed to live up to its high expectations. In February, the company posted its best quarter yet--it saw revenue growth of $286 million and daily active users increased to 187 million. 

Snapchat may have just learned the value of giving its customers what they want.