Does pbmining still ask for a 5 year contract? I remember that when I was looking for a cloud mining services. That's why I've chosen CEX.IO.
I think you can choose that or a 1 year contract. Some people buy GHs, mine for a month then sell the GHs at the current rate, making back their investment possible + the mining revenue.
I see you have gawminers in your sig. Have you got a miner with them? I am trying to decide between gawminers and pbmining.