Discovery. If you cross post and get more traffic to your medium post than the version on an official company blog then it makes sense to keep doing it.
It's not hard to believe Medium having more traffic than Tumblr, just wanted to understand how people measure this.
https://medium.com/@Medium/statistics-2971adaa615
https://help.medium.com/hc/en-us/articles/215108608-Stats
https://help.medium.com/hc/en-us/articles/215793317-Publicat...