Pop-up cookie lifetime
In Settings, add the length of time (in days) to the Cookie lifetime field to avoid showing the same pop-ups to the same person multiple times.
If you want the pop-up message to appear only once every 10 days, enter 10. Enter 365, and the pop-up will appear to your visitor just once a year. Leave the field blank if you'd like the pop-up to appear each time someone visits your page.