What does the display lightbox once per session rule do?
The display lightbox once per session rule displays the lightbox once per visitor per browsing session. Each time the visitor comes to your site, they will see the lightbox once. If they view it today, they will see it again tomorrow if they come back to your website.
This rule is great for delivering time-sensitive messages like current promotions, alerts, or things repeat visitors would want to do (like call you or request an appointment).