Only by using the pop-up blocker in your browser, and setting your ad preferences in your Comcast account. You do have some control over what ads you see. Underneath any ad on the right side of the screen, click on "Ad Info". Or just go to this link-------------
That will explain how you can opt out of some, but not all advertising. Or-----use a browser add-on called "AdBlock Plus". That should eliminate all of them.
Helped some but not enough. When I have to pay for internet service when traveling I don't need all that bloat. I've decided to switch to Google Mail.