I don't think most people from FB or Twitter are looking to jump to a platform like Steemit. Now going after Reddit users is probably the greatest idea. Most users on FB, Twitter, IG, or Snapchat, aren't interested in writing blogs or producing new content. They like to just update their statuses, share content others made, share news from other sites, post their own goofy pics and selfies.. all stuff you get blasted for here on Steemit and make zero $$$ doing, and once again, all those platforms are mobile. Reddit users would probably love Steemit if you can convince them to give it a chance. Although, the setup with subs isn't like Reddit, most of my Reddit friends don't like that everything is just #hashtag based. Steemit has a lot of work to do before any type of marketing will be effective taking their userbase.