Volume has to do with exchanges and exchanges have to do with volume. It's a catch-22.
I think exchanges will list the coin based on mining difficulty as well as volume. Thorcoin is getting more difficult to mine and supply will also start to dry up at some point. It doesn't seem like it now but it can happen. I expect if we land one exchange in combination with two cuts in payouts next month Thorcoin will be fine.
Exchanges can list super innovate coins or coins with really good community support in addition to trade volume criteria. Small exchange can pick you if you're a new promising coin. With current trade volume no exchange will be interested in adding thor.
If somebody can become a dev, that would be nice, but the premine should go to him aswell.