There's a style of commenting which (to me) sounds like it's written by American speakers with great, native English skills. And it seems to me like astroturfing...
I can spot Googlers (and relatively recent Xooglers) by their commenting style usually, with no other obvious disclosure. The funny thing about this, is they can be from wholly unrelated divisions from what they're commenting on, and not marketing people. Which is to say this isn't an accusation of wrongdoing here. They just have... a certain style that's distinctly Google, and it's kind of audible when reading.
I think it'd be really interesting to do some sort of data analysis on HN comment text, sorted by employer or country of origin, maybe known CEOs versus marketers versus engineers who comment, or whatever else, and see what patterns could be found. Are there certain sentence styles that correlate to different groups, or a noticeable difference in vocabulary?
I feel like most sites have a kind of commenting monocolture that's specific to the community on that site. For example, Reddit comments on popular threads can be indistinguishable from each other due to the use of "inside jokes" based around quoting a meme or something from pop culture. Everybody seems to comment in the same way in order to get upvotes from other users who "get it".
Twitter and Tumblr are similar in that users are often trying to write witty one-liners, which too end up leaning on pop culture references.
That said, what you are proposing could absolutely be used to suss out not astroturfers exactly, but fanboys of certain things. Jordan Peterson, Elon Musk, etc., they all comment in the same way when a critical article about them is posted on a message board.
