Advertising is "pay someone to say/show something about your product", where "pay" can refer to any kind of payment. It's really really easy to separate, conceptually, from any other discourse.

Now, there are situations where this is more ambiguous, and in general any display of a company's products or brands, especially one that is not critical, is suspect of being advertisement for that brand.

I'm not even sure how you can even claim that there is any sort of ambiguity between, say, The Raven and a Super Bowl commercial.