How do I get my pop up to stop popping up?

To whom it may concern,

I currently have my pop up to stop showing up once it has been seen by the same person 3 times. However, I have found that my pop up keeps showing up well after having been visited. Could you take a look at my site and see what is going on? I use firefox as my main web browser, so perhaps the issue is related to that? Any input you could give me on this would be appreciated.