Keia Clarke thought she had a handle on her surging customer demand. As chief executive of the New York Liberty, she runs the business of one of the WNBA's hottest teams, whose recent on-court success has led to surging viewership and sales of tickets and merchandise. To prepare for the Liberty's home opener at Barclays Center last spring, Clarke stocked the team store with fresh wares, including plush elephants modeled after the team's cult-favorite mascot, Big Ellie.

At the time, the Liberty was seven months away from its first finals appearance in two decades. Even with expectations for high demand, and careful inventory planning based on purchases of other novelty items, Clarke told me the store sold through a year's worth of Ellie plushies on the very first day.

The WNBA is one of the fastest-growing leagues in professional sports today, backed by the tech elite and flush with young stars like Caitlin Clark who helped double the audience for women's basketball from 2023 to 2024. The sellout of the Ellie plushie illustrates a bittersweet side effect of that success: Unlike other established leagues such as the NFL and NBA, the W is growing too fast for its teams to keep up with demand for jerseys, T-shirts, and toys.