MastCoin looks good, innovating features and something every coins will need in a near future : buying and selling anonymously from your wallet without accounts on exchanges.
It's just a matter of time before this coin goes up at least to 1 million market cap...
Exchange means BTC, not an illiquid coin like MAST.
Instead of paying about 1% to exchange DOGE to BTC on Mintpal...
You can pay 10% for the "convenience" of using the "CoinRecycler"... and going DOGE to MAST to BTC.
Unless they can find Market Makers...
To get that exchange spread down to low single digits... there is no value here.