> Will Akasha leverage existing social graphs (fbook, twitter, email, phone)

This is actually something we were discussing yesterday with Dr. Gavin Wood, one of the founders of ethereum and ethcore. It is a bit tricky to do without compromising the privacy of the users (associating an insecure form of identification to a key/address) due to the nature of blockchains, but there are a few interesting ideas on how to solve this issue. We’re looking into it but we need to experiment and see which one is the best before deploying something like this inside our application.

> Does Akasha plan to interoperate with any of them?

Social web 2.0 applications such as Twitter and Facebook are not necessary the friendliest when it comes to interoperability but as we will approach the beta we will look into making an API allowing interesting things to be done in an IFTTT fashion.

> Why is a blockchain needed? What aspect of decentralized publishing does this solve? Verifiability of content? Pub/sub relationships?

The chain removes completely servers from the picture and enables us to create a truly decentralized publishing mechanism by adding IPFS to the mix - since it is expensive to store content directly on chain, we're storing IPFS hashes on chain.

Besides verifiability and pub/sub relationships, identity/profile management and micropayments are also a big pluses that come bundled with the ethereum chain.

Hope this answers your questions!