Imagine an exchnage pairing USD with USD.
"Just send us your USD and you can trade it with USD"
No need to trade USD/BitUSD
BitUSD is like an altcoin to USD, it's pointless
If it's 1:1 how come it's trading between 0.91 and 0.99 here:
The price is different on bter because bitUSD on bter aren't actual bitUSD, they are effectively an iou from bter for bitUSD, or bterbitUSD, just like the bitcoin price is a little different on each exchange. The price is lower on bter because there is low liquidity resulting in a high spread, caused by there being low demaned for bterbitUSD. People don't bother buying it up because it costs more in fees to get money into bter and there are only a few sellers. You can withdraw bitUSD from bter (redeeming the iou) and it will be worth 1:1 against the USD, but it would have cost you more to buy, hence the discount, which balences things out.
At least I think I've got that right. bter could become a gateway and issue a bitUSD iou which they call an iou and can be traded against other ious outside of bter. At the moment the ious have to be kept on the exchange and are just called the same thing as the asset/coin, when in reality they are an iou held on the exchange.