I've read a pretty lucid (for a change) analysis of this over at /r/bitcoinmarkets<p>The gist of it was that BTCChina's long game was to kill all competition (by being first, and zero fees), wait for the surge of new users to taper off (market saturation?), and start charging a fee once they've monopolized the market.<p>The OP further speculated that they must've interpreted the change of regulatory climate as disastrous, expect a major exodus, and have implemented trading fees to get at least some profit off the activity.