They're not the same, that's true. What drew him to twitter was exactly what you describe: people get notified 2 seconds after he sends something out. The whole

They're not the same, that's true. What drew him to twitter was exactly what you describe: people get notified 2 seconds after he sends something out. The whole use-case of following public figures. That wasn't a thing (as far as I know) on Facebook back then. You had to have a 2-way connection ("be friends") with each person you followed. (I think? I may be misremembering.) It's how he won the presidency. But now the power structure is different. The President and his followers can turn Facebook into something akin to twitter just by using it that way. The mechanics of any given service aren't written in stone. Facebook could easily ping your phone whenever someone you follow posts something new. Or Instagram, Snapchat, etc.