I've just installed on the plugin on a website of mine: http://www.administratief-medewerker.com.
I've added a screenshot of my settings.
When editing the website I use Firefox. To test the actual popup I used Internet Explorer. On that browser I'm not logged in. I've tried both directly going to the site and going there through a search engine. The popup didn't show in both cases, even after waiting a couple minutes.
How can I get the popup to work?