Actually (and hilariously) Fox News according to their own court filings do not publish news, they are an entertainment product.
And I say ironically because that's exactly the mechanism people are clamoring for in this discussion: it's the courts. Lawyers argue and courts eventually decide definitions all the time, because it's highly impractical to belabor and endlessly debate passing new laws because we don't have ironclad definitions in them beforehand.
If you want my humble opinion, in a legal/ban sense, I would define advertising as:
> Communicative material that is placed strategically by publishers or media for a price/by way of other agreement to drive awareness of products or services with the intent to generate attention and sales of said products or services.