I was sad to hear today that Sonopia has failed. I previously thought Sonopia presented some interesting opportunities for more vertical applications (see Related Articles below).
While I don’t know much about what happened within Sonopia, I suspect it is it might have failed because people didn’t want to give up their existing phone, tariff or carrier for an affinity phone. Also, like many MVNOs, Sonopia probably didn’t truly distance themselves enough from the restrictions the underlying carrier (Verizon) nor expand into other parts of the World.
Update: Sonopia is not shutting down but "drastically scaling back its business and essentially hibernating… and looking at expanding into Europe".