I haven't done a deep analysis of the stats yet but will do so soon. I'm studying in Digital Marketing, so it would be worth to test out my own promotional capabilities.
However, Twitter has helped reach an external audience on certain topics, like cryptocurrency and digital analytics. I've found some followers that happen to be on Steemit too :)
As for Facebook, well, seriously it's hard to get people to read on that platform. I'm going to be creating a page soon, it might help reach more audience.
And finally, for Medium, I just started posting on it. I looked at their stats and seems my audience reach has been improving but it's really hard to get claps on Medium and followers if you aren't already a well-established blogger.