DO NOT invest into cex.io fees are insanely high and the profit is... lower than low. I lost about 0.3 btc because of cex.io.
And I still have no idea why someone will buy 1 GH/s for 0.0029 btc on cex.io now, in which he has to pay 80%+ of his mining revenue as maintenance fee.
The fee % was high, but it has never been that high, but it seems people there don't care at all...