Excellent article, full of drive!
I have been on Steemit for a little more than 2 months, and I am continuously amazed by its potential, and not only on the financial level!
Based on your 5 points, I would rank them SMTs as first , then communities followed by the Youtube adpocolypse.
The SBD rise, wow! I just entered before, and after 2 month gaining as high as 3-400 US$ worth of Steem for a good scientific post (about 6 hours work) is quite amazing.
I don’t understand clearly the rise of SBDs, neither do the main bosses (I watched the discord reunion with Steemit masterminds earlier this December). So I wouldn’t bet too much on it.
As for Alexa, yes, there is a rise, but this is not only due to the number of users, but also to the amount of use for each user (which can be very high on Steemit). Additionally, it only takes into account users with the Alexa toolbar, so the recent slight rise is statistically difficult to interpret.
What I see being the main driver behind the 2018 boost is Steemit as a social media platform. The friends I dragged on it, and sometimes by the toes, are now completely hooked, like me. And the addiction is not solely to the crypto gain, but to the amazing friendships they are building up here! Many are fed up with Facebook, and I can sense masses of Facebook users that will be fleeing to new horizons. And when they realize they can make money at the same time, well… human nature plays in our favor (for once ;-) )
3 months ago, I never has heard of Steemit. Since I joined, I converted 3 people that are becoming heavy users. One of theme, a techy, has even set up a node, downloaded the blockchain, and we are now reflecting together on new applications, probably oriented towards an improved research tool (very much needed on Steemit!).
2018 will definitely be a big year for Steemit and the Steem blockchain! And I am so glad I stumbled upon it a few months ago!