Just got done drawing this up on sketchboard.io - it's the non TL;DR version of how Agora Routing works.
The red text and arrows indicate the production of signatures for Proof of Service, the green arrows show who gets paid by the Validators.
People like pictures and it took me a little while to get over it and draw something up, sketchboard.io is a great site for this kind of drawing, even has hip looking pseudo-hand-drawn scribble style icons.
Updated to look prettier, I learned how to position the ends of the arrows arbitrarily.
Oh, some little explanation. The signatures are like those address things on courier packages, they contain the signatures from each stage and it's only when the consumer signs that the green payout line activates and new tokens are issued.
Dawn does not have a format of standard blockchain systems, just an easily readable log of transactions as they make it into the sequence. There is no possibility of timing attacks when all validators must vote to accept a new transaction and the client has to send them to every validator at the same time.
The database is replicated via a second run that delivers a digest of the last period of time since the last digest that also requires the full acknowledgement of every validator to be accepted by every validator. If there is a divergence greater 2/5ths the transaction is dropped, this is the condition of this history validation quorum. This is when all non-validating nodes can make sure they are up to date as well.
The precise parameters of dropping transactions will be more fully refined with the test network.
The essence of what this sets out to achieve is a network-wide replication of the database that is free of errors or divergence. This new idea about fixing the transaction in place while it is being gossiped about by validators, means there does not need to be a validation cycle, simply, a client sends a transaction to all the validators, who then compare each other's receipt, vote if it matches, and then the final transaction is then stuck at the head of the log and written into the databases, where it can be synced directly by trusting clients.
update
I have also removed the 'seed courier' because I realised that really is the Creator's client(s) seeding the file. The routing is created from the consumer end back to the sources where the files are being hosted, so it can be optimised for latency and geographical proximity.