Password sharing is normal. Netflix estimated more than 100 million households were using shared passwords, and The New York Times asks some readers to verify their accounts when a login shows up on too many devices. For your site, the bigger cost is the reader behind the shared login who never gave you an email address. This post covers how many devices to allow (four or five for consumer publishers, tighter for B2B and financial content), why tighter limits bring more support tickets, and how family plans and bonus seats turn sharers into named readers. See how the Times, The Washington Post and Mexico News Daily do it, plus one login test to run this week.