I've been using Medium for writing, recently with the notes from the Stanford 183C class taught by Reid Hoffman > https://medium.com/notes-essays-cs183c-technology-enabled-bl...

From the writer's perspective: 1) interface is clean and easy to write on - easy to format things, embedd video, embedd pictures, etc 2) easy to share drafts and get edits from others 3) 5%-10% of traffic comes internally from medium.com, so helps with distribution 4) SEO's well and works out of the box without me having to set anything up.

PS - I work at Greylock Partners which invested in Medium but I didn't have any say with the investment decision nor do I have to use Medium. I just like writing on there.