There are plenty of countries that would scoff at extraditing him for this simple fact of not having a treaty. Even countries that we do have a treaty with would've locked up extradition in the courts for years because he's facing life imprisonment for making a website and a bunch of other garbage they found on his servers:
http://www.latimes.com/business/la-fi-ulbricht-hearing-20131...
If convicted, Ulbricht could be sentenced to life in prison.
They're also charging him with paying to have someone killed merely based on chat logs. They even said there's no evidence anyone was killed or frankly any evidence at all other than the chat logs.
Let me translate that Russian for you: "We'll trade you Snowden for Poteyev."