They used to have zero revenue and deep investor pockets. Now they have growing revenue and still have deep investor pockets. There's ways for them to disappear, but fewer than there used to be.
Re: distribution. On a typical article, 80% of page views comes from within the Medium network through promotion by the Medium algorithm. Those page views (and even the followers of our publication) are readers that Medium sourced by publishing lots of other articles than ours. Their algorithm is much more reliable at driving 10k's or 100k's of readers than my other choices: mailing list, reddit, hackernews, SEO.
They aren't some scrappy startup anymore, they are the big dog in the space and doing those kinds of things doesn't exactly signal that all is well.
One question though - what do you mean by distribution?