CEX.IO lowers maintenance cost from $0.18 to $0.105 for 1 GHS per month by the means of upgrading hardware for mining Bitcoins in the cloud and arranging the lowest possible electricity cost terms for hosting ASICs.

Source: http://www.pressat.co.uk/releases/cexio-updates-mining-hardware-and-halves-maintenance-cost-at-companys-expense-2509c6edee5af7000bfc82c9897ca7fe/