Make sure to set the cookie duration so that visitors who have viewed and closed your Popup won't see it again until they've clear their browser cookies or the time you set is reached (default is set to 7 days). This means that once a user sees the Notify and decides to close it, then they will not see it for next 7 days. This way visitors don't get annoyed by seeing the same Popup every time they come to your site.
You can also clear your individual Popup cookies by clicking Clear this Notify Cookie button for testing purposes.
Set with -1 If you want to notify appear at any time. ( not recommended ) because it will annoying your website visitors.