For me, when I made my introduction video, I didn't plan on sharing it on Facebook with all my real life friends and acquaintances, but after I posted it to YouTube, I decided to share it on FB regardless. I do sort of like the idea of putting myself out there into that uncomfortable zone. They say that's where the magic happens, and I like that idea.

I had an overwhelmingly awesome response from my real life friends and family, and it was incredibly motivating for me. Now I actually created my own Facebook page that I have connect to my main account, where I post my content, and then I'll share it to my personal page as well. I accepted that fact that most people on Facebook (just like YouTube) won't be overly interested in my content, but there are the small percent that do actively give me feedback and ask when more content is coming out when I haven't posted for a little while, and that's incredibly motivating to me. It's also a great way to start your channel out. When you're first trying to grow, you should be trying to get all your real life friends/family/co-workers/anyone to subscribe to you to help hit that first 100+. This will definitely help boost your channel into a faster growth rate eventually.
So from my personal experience, I highly recommend sharing your videos on Facebook with your real life friends. I've had so many lovely conversations with people face to face (people that don't actively like or comment on my videos) that bring up my content right away when we run into each other, and tell me how much they enjoy it. You just can't have overly high expectations on FB feedback. Remember, your main audience is very much on YouTube, but it's definitely really nice to share with your RL friends as well.