I saw you are not new. If you want to promote Steem then why not add some text to the posts to at least say what you are doing? Even so, the post rewards are not deserved and people will continue to flag as your posts are regarded as spam and an abuse of the rewards system.

Has anyone joined as a result of your posts?

If you want to bring Youtubers here then do a proper post about it. You can feature several in one post. Just buying votes all the time is considered bad behaviour. You are not being part of the Steem community.