Once it's on the exchanges, more miners mine it and dump like crazy, driving the price down. You ideally want a period of relatively quiet building before going on to large exchanges.
Or you send it straight to Cryptsy and watch it get sold into the ground. Because that's exactly what will happen.
Or the counter argument is that once its on Cryptsy, lots of BTC holders will jump in and buy for a profit. Obviously MOON has a lot more potential to triple than their stupid BTC. That has maxed out and no one should hold on to BTC.