Not so long ago, I noticed that some of the sponsored stories served up in my news feed were exactly the opposite of what I wanted to see. As a committed couch potato, I was repeatedly being offered ads for running equipment, gym memberships and worse. Why? I wondered.

If you’ve ever been frustrated by a similar occurrence, here’s why, what you can do about it and– most importantly– why this is relevant information for marketers…

How does Facebook work out your interests for advertising?

The fact that the network compiles information about your preferences based on things you talk about often and the subject of links you click on is certainly no secret.

This is what makes it such a powerful tool for advertisers, allowing them to reach out to an audience who have actively expressed an interest in their product.

A lot of the time, you find the ads Facebook offer up to you are spookily spot-on. That’s hardly surprising, given that you’re likely to be talking quite a lot on Facebook about the things that are important to you.

If your profile of interests is compiled based on frequent mentions and engagement, it’s little wonder that some undesirables will sneak in there, too– after all, one of the primary uses of Facebook is having a good old whinge with your friends.

Frustratingly, it seems that when collecting information about your interests, Facebook doesn’t take into account the sentiment of what you’re saying.

So on the multiple occasions I’ve said I hate exercise, it seems I’ve inadvertently signalled to Facebook that I’m interested in that subject– and I’ve been served ads accordingly.

Exhibit A

Why should you care?

So the frustrating mystery of totally inappropriate ads is solved. But why should you care?

On an abstract note, it’s interesting to check out your list and see what weird and wonderful things Facebook thinks you’re interested in.

You can access your full advert preferences list by going to the settings menu on your Facebook profile.

From a more pragmatic standpoint though, giving your ad preferences a spring-clean can radically improve your Facebook experience.

As well as culling any unwanted interests (goodbye, ‘health clubs’), you can add in any interests that Facebook might somehow have missed.

That means you can make sure the ads you’re seeing are the ones that really interest you. You’ll be served relevant products or articles with no extra effort on your part.

How is this knowledge useful for marketers?

This should be a reminder to marketers to be as specific as possible with their targeting.

Though someone who isn’t interested in your ads is unlikely to click through and cost you money, they are likely to report your ad as irrelevant– which will lead to a lower quality score and more expensive ads for you.

If it’s possible, use other targeting options, such as using email address data to have Facebook compile a lookalike audience for you. This lets you match individuals to your audience in a more holistic way, instead of by isolated interest alone– which, as we’ve seen above, is far from foolproof.