Based on my limited experience, they key metric, apart from views, is the total reading time. If the article is short but has lot of visits, revenues will be low.
As a writer, you simply need to sign up for Medium Partner Program (and complete the KYC sending your ID, bank account details, etc.). They pay quite well (the first week of each month).
Medium gets revenues from premium users who pay $5 per month and distributes all the revenues based on views, reading time, etc.
