The DIFFERENCE for Steem from Facebook, Twitter, etc. is that people can give you money with their MINDS rather than their wallet because the upvote doesn't technically cost anything and even with a very small amount of steem, those upvotes can add up, the platform is decentralized, it is censorship resistant, and soon Smart Contracts in the form of SMTs, creating a new level of flexibility on the blockchain, will allow for additional functionality that has yet to be thought of or implememted. Additionally, user data is not kept and sold by the steem blockchain; it is transparent through the blockchain explorer. Those are my thoughts on the matter anyway. :)