It's a great site, but the one problem I have is that they're working off of a very informal definition of what a trope is. If you go by actual narratology studies, a trope would denote the way a story is structured. It's unfortunately the only instance of the term where using it will get you credit in an academic circumstance.
I've seen frosh types in the Bachelor's actually cite it in their essays. Okay, so it's kinda fun if you're lucky enough to study in a university that has a bit of leeway concerning the seriousness of your academic pursuits - but that really varies from teacher to teacher. I've gotten feedback on stuff I corrected that was received by teachers around my age (so the Troper tics were left to fly under the radar) and older professors who develop facial spasms if you bring up the term "Badass Longcoat" in the same sentence as "Hero's Journey".
It's a great site, but I tend to use the same policy I keep for Wikipedia. That is, cite the documents that are being cited by the page as reference. Never cite a trope page or a wiki entry, lest you get your work hacked apart by vindictive pedagogues...
Never directly, at any rate.
Personally, though, I'm a big fan of scrolling through tropes associated to my latest book or game purchase, or to try and see if there's any stylistic siblings to something or other I happen to like.