Four requests to update their card on file (the day of the failure, the next day, three days after that, and seven days after that). Then the account is suspend

Four requests to update their card on file (the day of the failure, the next day, three days after that, and seven days after that). Then the account is suspended. The whole "drip campaign" for dunning mails is a SQL query, two prewritten mails with some placeholders, and 21 lines of code that runs as a cron job once a day. Recommended reading: https://training.kalzumeus.com/newsletters/archive/rainy_day_ideas https://training.kalzumeus.com/newsletters/archive/rainy_day... http://images1.bingocardcreator.com/blog-images/hn/sample-dunning-email.png http://images1.bingocardcreator.com/blog-images/hn/sample-du... If the user logs in to a suspended account, they're welcomed back and asked to update their payment information to reactivate the account. All their data is still waiting for them. Lots of people that disappear come back and reactivate at some point in the following months.