One thing this piece really brings home to me is how unethical it is for media to sell sponsored content intermixed and indistinguishable from their own content. How do you trust a media outlet when their content is for sale? I know this practice pre-dates the internet, but it's hugely damaging to people's faith in the media.
I think Facebooks' failure in PR is more a symptom of how far Facebook has slid down the ethical slope into outright corruption. As you do more and more heinous things, it becomes more difficult to defend those actions.
In this specific case, it was clear Teen Vogue and Facebook were trying to do exactly that, and the fact that they pulled it suggests to me that omitting the "Sponsored Content" warning was part of the terms of the deal. I suspect this is extremely difficult to police and people get away with it all the time.
I think Facebooks' failure in PR is more a symptom of how far Facebook has slid down the ethical slope into outright corruption. As you do more and more heinous things, it becomes more difficult to defend those actions.