If you see a purple, orange, or white check mark badge on Substack today, that is a bestseller badge which identifies the writers and publications on Substack who have a high number of paid subscribers.
Unlike a verification badge seen on other platforms, the only way to earn one of these bestseller badges is to start and grow a paid publication to hundreds of subscribers.
Bestseller badge on a Substack profile
Bestseller badge in Notes
Learn more here about Substack Bestseller badges.