After asking about it in another thread (https://premium.wpmudev.org/forums/topic/pop-up-plugin-showing-immediately-despite-on-click-add-on) I received help to realize that the pop up! plugin will only appear once per page load. So when someone sees it on your site and they close the pop up, you have 2 options: they can close the pop up forever, and it will never appear for them again, or it will close and show up again ONLY if the person reloads the page. I would like to request a feature where a third option is presented which allows the pop up show multiple times for a single page load. This may sound annoying, but it works for me because I am also using the on click add-on, so my content loads whenever a user requests to see it by clicking a link. Think of it in terms of how Facebook uses inline pop ups to view photos on your news feed, or longer status updates, etc. That's basically what I want. I want a user to be able to click something, have the pop up appear, be able to close it, and re open it again if they feel like it.
Hope I explained it well enough.