Good article with examples on effective triggers to keep people coming back to your site. You need to keep your business in the minds of customers.
Indiehackers uses digest emails to help users keep up with what is happening in the forums. Loom sends a message when someone watches your video. Medium tells you how many people have read your articles. Product updates are a good way to keep users updated. Desktop notifications can be annoying but they work. Share links to access more content and referral bonuses encourage more sharing.