Spondoolies Tech seems to indicate that PBmining it's a ponzi:
This is not endorsement to buy CBCM, but I look at PBMINING cost. The electricity alone for 5 years cost a lot more than the contract cost per $/GHs
Either it is a pyramid or they expect to replace with new hardware at an unrealistic rate. Do the math.
Guy
quoted from
https://bitcointalk.org/index.php?topic=647360.0.
i am also confused with their low rates.No one can provide this service on these rates.it looks like a ponzi or hyip