There are few Youtubers that are doing a pretty good job at promoting this site like Vincent Briatore, Doug Polk Crypto, etc.
I joined this site like a week ago, and they were the main reason I joined this site, alongside with my brother who's been a member here for a month.
You just read my mind, been following Vincent and Doug for a while, they have huge followings on youtube. This is just the beginning, I see tons of youtubers with huge followings are marketing Steem and D.tube heavily. :)