Sometimes I read hilarious stuff written by students. I've read clearly stolen re-summaries of existing shows, fanfictions of existing fiction submitted for creative writing assignments, and stuff. Sometimes I read pretty good, original short stories from a budding talented writer.
I also tend to use the same standards I check high school student writing to judge the quality of webcomics and webnovels to read too. Is there a conflict? Is there a theme? etc. My pet peeve is being asked to check out a series only to see that their description/summary basically tells me nothing and doesn't make me curious to find out more.
I have some general knowledge of market audience since many of my students like to read webtoons, apparently.