There is some discussion about this on Hacker News too:
Red Hat’s ramping up the pressure on Ubuntu by going deep on another cloud provider’s platform. The Linux spinner’s Gluster Storage shared-nothing, file storage system is now available on Google’s cloud platform. Red Hat hopes to boost its fortunes by making its Linux-based infrastructure code available as an option to those …
The reason Ubuntu succeeds..
Is because it's completely free and even the LTS maintain relatively recent packages... Which developers love! Flip side though, Redhat has far better applications, support and better support from 3rd party software supplier's.