I dont think crypot coins are product and services which can get sold anywhere they want. This is actually critical part really and coins getting over an exchanger can be perfect way to attract more supporters for the project. Even when there is voting or some sort of competition for listing then I have seen community stands up for that coin to get listed as fast as it could. So you can imagine how important it is really.
Whether it is centralised or decentralised all that matters is good support, good volume.