I thought of this as how the boundaries of storytelling and narratives are being recorded as devices. TV tropes are almost like a language you didn't even realize you spoke.
"What is this about? This wiki is a catalog of the tricks of the trade for writing fiction. Tropes are devices and conventions that a writer can reasonably rely on as being present in the audience members' minds and expectations. On the whole, tropes are not clichés."
If you've not enjoyed an episode or several of Mystery Science Theatre 3000 (or MST3K), this article provides and excellent overview. Hodgson teaches a master class on riffing, focusing on the art of storytelling and relating it both to the story being told (film) and the audience experience. Interesting points are also lightly touched on regarding the implications of something like movie riffing in the age of social media.
Also, if you've not done so previously, I recommend RiffTrax, the downloadable mp3 tracks meant to be played along with popular, contemporary movies, as opposed to the B-list flicks riffed on in MST3K. (These tracks are not paired with the movies themselves due to, of course, copyright issues.)