I lost a little interest when I read that it's an extra step on top of Runkeeper (which already lets you share runs), then I lost a little more interest when I realised that sharing to Twitter was yet another step. Then they completely lost me by requiring Facebook, which I don't use and never intend to.
Hear, hear on the Facebook comment!
Nice landing page design and cool little intro screen animation to the app, but I don't have a Facebook account.
I would love if this connected to Moves! That's how I keep track of all my runs.