WhatClinic, a medical treatment directory, struggled with its call tracking solution, which was plagued by variable costs per call, poor connectivity issues, and lack of transparency into the charges. The company eventually switched to Twilio in 2011, which provided them with a more reliable and flexible call tracking solution that allowed them to analyze customer communications in detail. This switch enabled WhatClinic to accurately track phone leads and show treatment providers exactly how many calls it generated for them. As a result, WhatClinic discovered that phone calls converted into actual sales at a much higher rate than emails, making the call tracking solution crucial for supporting its claims with data.