I had a similar problem ... believe it or not ... with RV.net yesterday. My son, who is a little more of a computer guru than I am, told me when clicking on those apparent 'ads', code is actually embedded in the browser, and when landing on certain web pages, they pop-up in the middle of the page. Mine was attacked on Firefox, and only on RV.net. My son figured out it out and un-installed the program and code that caused the problem.
He said, one way to get rid of the imbedded code was to delete Firefox completely and re-install it. This type of code (for this stupid dumb A** advertising) attacks specific browser. So if you switch to a different browser, it will probably work just fine. Try that.