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just because one can post something on Reddit and Facebook, they cannot be the same. it comes down to the features which make it different from each other. Steemit is not for messaging whereas one can make video call and chat with each other in Howdoo. Thanks for pointing out the spelling errors and im not saying that Howdoo is better than Steemit so dont get me wrong. I love Steemit and i also like the idea of Howdoo.

What about http://d.tube and what about the others?

dtube is a decentralized take on youtube and it is one of the 300+ projects built by steem community. Steemit is a platform mainly for content whereas Facebook is mainly for the social connect.