When I buy or sell coins I get the message:
"Your entire order can't be filled at that price. What remains is stored in your open orders."
Then when I look at my order, none of it has been filled.

If there are really no offers on the market I would like to see that.
Also it would be nice to see how much volume is available to buy or sell at a given price before buying or selling.

Thanks for putting up another exchange, I like bitcoinmarket but competition is always healthy.
I think there are several advantages to your site even with the transaction fee that give the traders more opportunities.

One thing I really like is that you have an account in dollars so I don't have to make a lot of paypal trades. Paypal gets kind of suspicious of this.
Another plus is the default prices taken directly from the market. This reduces errors in order submission.