The basic idea of Medium is simple enough. Bloggers are encouraged to publish posts to Medium. These posts will receive visibility on the Medium site according to their popularity with readers. Bloggers can submit their post to "collections" which are subject-matter groupings that are monitored by editors -- each editor may accept or reject a post for inclusion in his collection.
The goal of Medium seems to be to encourage longer and more considered posts than we typically find on most social media sites. In a sense, it is a like going back to the earlier days of traditional blogging when bloggers tended to take a lot of care with each post. The big difference with Medium over those traditional blogs is that Medium is essentially a mega-blog with lots of topical categories, and it is social media friendly by design.
The functional design of the Medium site is well executed. Writing and editing a post on Medium is simple, and the results are elegant. The posts and any images associated with them are nicely presented to the reader. It is an enjoyable site for both the writer and the reader.
Rumble Press recently joined Medium and submitted our first post, "David and Goliath (and Enron): 'Why Should I Read Blogging Enron?'". So far, that post about Blogging Enron has been selected by the editors for inclusion into four collections, "Good Reads", "Justice and Freedom", "Under 5 min reads", and "Business Daily: Startup, Development, Management."
Check out the Blogging Enron post on Medium -- it provides a great introduction to the site. And if you enjoy the post, please recommend it!
At Rumble Press, we like Medium.com, and we will be submitting additional posts to Medium over time on a variety of topics. So stay tuned!