Unfortunately on Facebook, self-promotion is all about stealing viral videos and posting them. Since Facebook doesn't punish content stealing, this is what grows FB pages the most. I don't make money from my Facebook page so I'd rather keep my Facebook page aligned with my brand.
YouTube does punish for stealing content so self-promotion is much harder on YouTube. YouTube channels rank based on their 'minutes watched' so the best way for a YouTube channel to increase their views is to have longer videos that hold people's attention (surprisingly hard).