I'm not sure if this is the case with just me or something really changed got changed behind the scenes, I've been seeing less of these 'sponsored' stories lately since this news created buzz sometime back.
In my own case I've come to see "likes" as a liability and removed all existing "likes" for commercial organizations or any uncommercial org for which I see these paid-for posts. Hardly the desirable outcome for Facebook or the organizations! I hope my reaction becomes more prevalent.