She really is a nasty piece of work. That was a completely uncalled for response.
Also, pretty much every successful youtuber will say, listen to your audience. You learn from them to learn what they want and will therefore watch. That's how you grown your blog/channel/social media. No views = no money.
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I know I've mentioned her before, but Carrie Hope Fletcher has taken this attitude to her followers. This has resulted in engagement plummeting, bad PR when she was in a west end show, and now she barely gets any theatre work beyond one off concerts and her solo stuff sells less and less. Think she is also likely black listed by Andrew Lloyd Webber.
If she keeps this up, her attitude will bite Jen in the arse.
Also, by publicly replying in the q and a she is showing all her followers what a nasty attitude she has. If she had ignored, or responded in dms it would stay between her and whoever asked the question.