Actually the trade design of CoinMarket prevents a lot of the manipulation you see on the other exchanges.
It does not allow coin to be purchased for more than the current lowest sale, so in my mind, it keeps it far more legit than the larger exchanges do.
Every purchase is a real purchase, so no one can go in and say buy 10 DGB for 1 BTC to boost the price.
I've been talking on and off with them and quite a few people using the exchange and most seem to love the design.
Not to mention... THIS IS JUST BETA!! It's going to get even better!