I was surprised today while on Facebook to notice an advert on the left of the page with the face of a friend of mine promoting a certain local radio station. It looks like this may be due to the SocialAds system in Facebook, which seems to be a way to persuade people to but products on the basis that their friends are a fan of it so you should too. Unlike celebrities though, your apparent endorsement of a product won't earn you a penny, in fact you may not even be aware that this is happening. The products concerned don't seem to be completely random but may be products that you are a "fan" of.

Fortunately though, there is a way to opt out of this system. By default people on your friends list might see such adverts, but you can make sure nobody sees them, the setting is a little hidden away, but this is how you find it:

• Click on Privacy at the top right of the Facebook webpage
• Click on News feed and mini feed
• Click on the SocialAds tab
• You will see that there are two settings available - "Only my friends" and "No one"
• Set to "No one" to opt out of the system

Hopefully that should do the trick. I do find this sort of advertising system slightly creepy and I hope this sort of thing does not catch on. Having your face used to promote a product should surely be "opt-in" rather than "opt out"?