I like how the comments to your legitimate complaint are telling you there isn't a problem.

Remember popups from the 90's? This is a popup. And it's both annoying and unjustified; offer people to keep updated or fill in a survey once they've visited your site a couple of times, kthx. And don't do popups. Never do popups.

Why didn't you just click on the 'x'? I did not even notice it, and thought the article was well worth the read.

I didn't experience that at all. If I did, it was so unobtrusive that I don't even remember navigating past that. You missed a great article.