“ Tons of people have bigger audiences, but they all started where you are.” — Linda Caroll

This is not exactly true. Most of the people on Medium who have thousands upon thousands of followers are writers (mostly tech and business writers) who have been writing on the internet for 15 to 20 years and who had already built up a following of thousands of readers. When they came to Medium they brought most of those followers with them so they started out here with thousands and thousands of followers.