Thank you @pfaffman. I don’t understand your solution. Are you talking about:
- Create three different ads with the different class names (.first-ad .second-ad, .third-ad) and set them visible on all three categories.
- Custom the categories CSS style (I’m not sure how to do this) to hide some ad depends on their class name (If I don’t want to show the second ad on category A. I would add .second-ad {disable: none} to the CSS style).