It works on several sites (I've been using it for many days) and it's great that I can block specific parts of pages without having to use another add-on (such as "Element hiding helper"). But, for some reason, even though I'm subscribed to several lists it doesn't block a SINGLE THING on http://brittanica.com/ (This is probably true for other sites as well.)

Even if I create special rules to block the ads, I re-load the page once or twice and new ads are displayed.

This is very annoying, this not "non-instrusive" advertising (and I have that setting unchecked, by the way) we're talking about ads with moving images and lots of blinking non-sense, right next to the article.

Adblock Plus allowed me to use the Encyclopedia Britannica site without any disturbances.