I don't see point in 0% fees. Why would anyone run a business without making profit on it? It smells shady.
Bitcoin exchanges fees are huge compered to other markets but 0% is not normal.
They may make money from lending. From Huobi's site (Google Translate, slightly edited):
国内首家提供借款借币的比特币、莱特币交易平台,无论涨跌,在火币网您都能轻松获利
Provide the first domestic borrowing by currency Bitcoin, Litecoin currency trading platform, whether up or down, the Huobi net profit that you can easily
Huobi at least has fees for withdrawal:
火币网支持以下现金充值方式
火币点卡充值0手续费,7×24小时实时到账
银行汇款0手续费,火币网收到汇款后2小时内到账
处理时间09:30--19:00
火币网支持以下现金提现方式
银行卡提现手续费0.3%--0.5%,24小时以内到账
处理时间09:00--18:00
DEPOSIT
Huobi net cash recharge way to support the following
Huobi TOPUP 0 fee, 7 × 24 hour real-time arrival
0 bank transfer fees, Huobi remittance network within two hours after receiving Daozhang
Processing time 09:30 - 19:00
WITHDRAWAL
Huobi network supports the following cash-way
Bank card withdrawal fee of 0.3% - 0.5%, less than 24 hours Daozhang
Processing time 09:00 - 18:00
I understand that they issue their own card, good for deposits ("Huobi TOPUP" above).
Their withdrawals seems to be a little bit faster than MtGOX.