This is what I do
I do magic, and I use my Instagram account to post, short 5-35sec magic clips along with photos of my career, life and other fun stuff(most often magic related). Instagram is cool too because it has that hashtag system that makes you reach millions of people with the same interest as you, AWESOME i know.
Now how does this relate to youtube? Well in my case I have my Youtube link on my Instagram page, so If people like me on insta and digg what I do, they might hop over to my YT channel and check it out, and hopefully love it.

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My YT is also different, there I make little bit longer videos, reaction stuff and talk more. So its not the same.
Does this make any sense to you?