PSNow is not a world wide service. From what I believe PSNow runs off Gaikai which is only used in some parts of the world. From memory Gaikai cost Sony roughly $500m. Now if you put that into comparison with Azure, that cost MS $30b which is accessible world wide. Something I don't think Sony can afford unless they rent out Amazon or something. I will be curious to see how Nintendo and Sony imitate and implement this rumoured Xbox direction. Nintendo could possibly rent the servers out from MS and have there own access but I don't see Sony doing that as there relationship with MS isn't the same.
Sony can also rent out Azure.
If Microsoft succeeds in this endeavor, it will end up being fantastic advertisement for one of their most lucrative and fastest growing businesses.
I'm not up to speed with how azure and other cloud businesses are structured ,but would I be right in thinking the biggest factor in cost and the reason azure is worldwide is its focus isn't just gaming whereas Now is specific and Sony if it just keeps to game streaming could expand it at considerably less cost since it doesn't need to replicate azure in it's entirety to gain coverage , like Pemalite said it could rent from Azure or Amazon what it needed leaving them space to consider how they move forward with it's Now network , plus if its a slow take off they only need to rent enough to cover their needs.