Cart abandonment, tips on how to stay safe online, requests to go paperless, newsletters, claim your free subscription that came with your purchase, thank you for your purchase (separate to the order confirmation), requests to leave a review, continue your application, offering support, "you haven't logged in for a while", new login from $device, thank you for completing step X ... it's endless.
An endless torrent of excuses to get the their company name in front of your eyeballs.