Devs are currently testing a new feature that will allow us to rate the quality of the ads, it looks like this:
The problem is that many of the visitors interested in ads will first click them, and probably never come back to rate them; on the other side, the ones that dislike them will almost always take the time to rate them.
There are two solutions to prevent losing potential positive feedback from clickers:
Use the current feedback and when someone clicks on them, mark them as positive
Remove the current feedback and get the successfulness or failure of an ad using the click-rate instead of manual rating