Unable to solve the challenge of how to support positive behavioral change, Dick Costolo, former CEO of Twitter, decided in February to shut down Chorus, a social fitness app that began beta testing in April 2017. The app was designed to use a “chorus” of friends as team members and have them support each other in achieving self-proclaimed weekly fitness or other health-related goals.

Reasons cited for shutting the app down included the facts that people did not continue using it over time and that users who failed to meet goals tended to avoid their support group rather than turn to it for help.

In an email to beta-test users that was shared on Twitter, Costolo wrote, “We don’t want to replicate many of the existing business models of digital and real-world fitness that are based on ‘breakage’ (people pay for long-term use and then don’t really use the platform). We are more interested in solving the churn and motivational dip problem, and we just couldn’t get there.”

Costolo has participated in six startups and has founded four, according to Business Insider UK. His startups include Twitter, Feed­burner and Spyonit, among others.