Their fees for cloud mining are on the high side.
this is simple the reason is because 50% or more of the blocks you earn in a day you are actually loosing BTC. they charge you maintenance fees on every share the cloud submits but they only pay you reward on N number of shares from their PPLNS pool setup. So you will get a reward for a 1 hour to 3 hour block but the fees are higher than the reward resulting in you loosing BTC on 50% or more of the blocks mined in a day. they roughly solve 29 blocks a day here is an example of the payouts for 1 day resulting in an overall loss of BTC for the day. the below calculations are based on only 2 GHS of thier cloud imagine if you had more.
The thing they also do is if you have machines pointed at the pool and you own cloud there you will have to look very closely to see these losses. If you want to find out, take your machines off the pool and point them somewhere else and just let the cloud you own run by itself. Then you can see by owning cloud and pointing machines there it is costing you BTC thast your machines are paying for in the end. when the reporst show you your earnings it combines your cloud reward with your machines reward so you wont see the reward on your cloud was lower than the fees involved in the cloud.
Dont take my word for it, point all your machines to a different pool for 5 days, then go check you reward stats on Ghash.io. I bet you will see a lot of this
2014-11-08 05:46:26 -0.00000207 BTC 0.00002494 MAINTENANCE - Shares 4096 , Cost: -0.00000207
2014-11-08 05:46:26 0.00000102 BTC 0.00002701 MINING - Block #329005, Reward: 0.00000102
LOSS OF 0.000001052014-11-08 03:19:20 -0.00000259 BTC 0.00002549 MAINTENANCE - Shares 5120 , Cost: -0.00000259
2014-11-08 03:19:20 0.00000102 BTC 0.00002808 MINING - Block #328991, Reward: 0.00000102
LOSS OF 0.000001572014-11-08 00:02:09 -0.00000181 BTC 0.00002682 MAINTENANCE - Shares 3584 , Cost: -0.00000181
2014-11-08 00:02:09 0.00000102 BTC 0.00002863 MINING - Block #328974, Reward: 0.00000102
LOSS OF 0.000000792014-11-07 21:51:55 -0.00000130 BTC 0.00002710 MAINTENANCE - Shares 2560 , Cost: -0.00000130
2014-11-07 21:51:55 0.00000102 BTC 0.00002840 MINING - Block #328965, Reward: 0.00000102
LOSS OF 0.000000282014-11-07 20:25:40 -0.00000104 BTC 0.00002738 MAINTENANCE - Shares 2048 , Cost: -0.00000104
2014-11-07 20:25:40 0.00000102 BTC 0.00002842 MINING - Block #328957, Reward: 0.00000102
LOSS OF 0.000000022014-11-07 19:30:42 -0.00000156 BTC 0.00002740 MAINTENANCE - Shares 3072 , Cost: -0.00000156
2014-11-07 19:30:42 0.00000102 BTC 0.00002896 MINING - Block #328953, Reward: 0.00000102
LOSS OF 0.000000542014-11-07 17:34:39 -0.00000105 BTC 0.00002744 MAINTENANCE - Shares 2048 , Cost: -0.00000105
2014-11-07 17:34:39 0.00000102 BTC 0.00002849 MINING - Block #328944, Reward: 0.00000102
LOSS OF 0.000000032014-11-07 15:02:34 -0.00000158 BTC 0.00002604 MAINTENANCE - Shares 3072 , Cost: -0.00000158
2014-11-07 15:02:34 0.00000102 BTC 0.00002762 MINING - Block #328926, Reward: 0.00000102
LOSS OF 0.000000562014-11-07 10:55:11 -0.00000136 BTC 0.00002463 MAINTENANCE - Shares 2560 , Cost: -0.00000136
2014-11-07 10:55:11 0.00000102 BTC 0.00002599 MINING - Block #328894, Reward: 0.00000102
LOSS OF 0.000000342014-11-07 07:43:29 -0.00000105 BTC 0.00002202 MAINTENANCE - Shares 2048 , Cost: -0.00000105
2014-11-07 07:43:29 0.00000102 BTC 0.00002307 MINING - Block #328869, Reward: 0.00000102
LOSS OF 0.000000032014-11-07 06:41:20 -0.00000298 BTC 0.00002205 MAINTENANCE - Shares 5632 , Cost: -0.00000298
2014-11-07 06:41:20 0.00000102 BTC 0.00002503 MINING - Block #328867, Reward: 0.00000102
LOSS OF 0.000001962014-11-07 04:01:07 -0.00000210 BTC 0.00002401 MAINTENANCE - Shares 4096 , Cost: -0.00000210
2014-11-07 04:01:07 0.00000102 BTC 0.00002611 MINING - Block #328849, Reward: 0.00000102
LOSS OF 0.000001082014-11-07 00:17:47 -0.00000132 BTC 0.00002105 MAINTENANCE - Shares 2560 , Cost: -0.00000132
2014-11-07 00:17:47 0.00000119 BTC 0.00002237 MINING - Block #328827, Reward: 0.00000119
LOSS OF 0.000000132014-11-06 23:12:02 -0.00000420 BTC 0.00002118 MAINTENANCE - Shares 8192 , Cost: -0.00000420
2014-11-06 23:12:02 0.00000103 BTC 0.00002538 MINING - Block #328819, Reward: 0.00000103
LOSS OF 0.000003172014-11-06 19:04:58 -0.00000132 BTC 0.00002435 MAINTENANCE - Shares 2560 , Cost: -0.00000132
2014-11-06 19:04:58 0.00000102 BTC 0.00002567 MINING - Block #328798, Reward: 0.00000102
LOSS OF 0.00000030Based on these calculations a member with 1600 GHS on Cex.io cloud will actually LOSE 0.00947792 on his cloud mining for the day.