I've considered it for a while, but haven't done it yet. I saw a video a while back about it and the guy gave his strategy on it. He would create the ad like normal but deactivate it on mobile and Insta because FaceBook opens YouTube in its built-in browser on mobile and same with Insta, most people aren't logged in to YouTube on them so they can't subscribe. So he ran them only for desktop users because it would take people straight to YouTube with their account already logged in. Again, I haven't tried it personally but seemed like a pretty good strategy.
That's pretty useful to know, actually! I tend to be logged in on mobile but I hate not having it open in the app, heh.
I've been using ads for a while, but that's mostly because I upload my videos onto Facebook as well and promote them there. For me, getting recognition on an alternative platform is not a bad thing - provided the message I'm still aiming to get across is received coherently. I've had a lot of extra views, although not as much engagement as I'd have liked, which can make it very obvious that more of your views are paid for rather than organic. That being said, I do have a smaller but very loyal audience, so perhaps my organic growth will increase in time.
Another thing to add; when marketing my vids, I have a tailor-made audience with specific interests in
education & linguistics, meaning whoever sees my work is someone who actively wants to.