With 1.5 million active users on Facebook each day, it’s a tall order to make sure advertising is relevant to each and every user. Most of the time Facebook advertising is direct hit: targeted offers, relevant updates, great news from brands we love.

But sometimes Facebook advertising is annoying, irrelevant or just plain offensive. You know the drill. You’re minding your own business stalking an old high school friend’s photos when suddenly you see an ad for a woman peeling her face off. Yikes! And yeah, I know I stacked on a few kilos in the USA but do I really need to know One Crazy Trick to Lose Belly Fat? Really?

Now Facebook has unveiled one crazy trick of its own to help better understand why its users are switching off to certain ads.

It’s common knowledge that users can hide any story in News Feed and that includes ads, by simply selecting the ‘I don’t want to see this’ option from the top right corner menu on each post. Now users can provide additional feedback to let Facebook know why they have hidden the post.

This feedback step is optional. After a user has hidden a post they will see a box that advises that the post is now hidden. Click on Why don’t you want to see this and users will be presented with a short survey where the user can nominate his or her reason from a range of options including it’s not relevant to me, it’s offensive or something else.

“When testing this update, we looked at when people told us that ads were offensive or inappropriate and stopped showing those ads,” says Facebook product manager Max Eulenstein. “As a result, we saw a significant decrease in the number of ads people reported as offensive or inappropriate. This means we were able to take signals from a small number of people on a small number of particularly bad ads to improve the ads everyone sees on Facebook.”