How do other world systems work with bid and ask spreads? ie stocks, currency spreads on world markets? Are there fees involved?
In most markets, it is free to create a buy or sell order (and it's free to cancel the order). There is usually a fee/commission only if the trade is actually executed. This is the way it already is on Mt. Gox. If there were a fee to create orders, this would reduce volume and liquidity in the market. We want more volume!
I don't think there should be a fee to place or cancel orders. There should only be a fee when a trade is executed (as it is now).