I've already shared here my method with FB groups, here's my thread to make money on video uploading & sharing, which also involves FB posting and Youtube commenting. I usually use this algorithm with AdSense ads, but you can choose whatever you like.
Create a video uploading site.
Post 10 or more engaging videos a day (it can be home/nature/animal/beauty/etc videos).
Create Facebook public page with the same name as your website and post your videos there.
Join numerous Facebook groups and share video posts one by one from your FB page to those communities and grow your audience.
Go to YouTube and look for the most popular latest movie trailers. Write comments like this: “Can’t wait to watch this movie. While we are waiting, there’s something amazing for all of us.” Put your link there.
Build your offer into the shared video.
Cheers, you got your traffic for free