It looks like HealthUnlocked's new sponsored post trial has begun - see the Echo post below - the one with medicines spelt incorrectly (although I'm sure they'll correct that soon).
You can click on the post to find out more or if you want to remove it, you can just click on the cross in the right hand corner of the post and it will disappear.
Fran
Updated: You will probably only be able to see the sponsored post if you are registered under a UK address (and possibly only in England as the service being promoted is only available in England as far as I'm aware).