This is one of the coolest things I have seen in a long time. Reminds of how Meteor first started off with it's cool Pub/sub features. Watched the entire walkthrough, Kudos to you. Having worked in cache invalidation field, I know for sure that it's a hard problem.

The pricing is pretty cool. Free for non-commercial and <200k projects. I know what I will be hacking on tonight.

Kudos to the team