Although Gaana doesn't describe how theirs functions, CDN's typically cache content to speed up load times and improve reliability of content. This is great for users.
However it is my understanding that this can make analytics less accurate and reduce our flexibility as podcasters to make quick changes to the episode if need be.
Let's say I need to pull down an episode quickly. If I use Gaana CDN the episode will still be served becasue users are not downloading it from me, they are downloading if from Gaana's CDN which still has the episode available until it is updated at some point in the future.