I hope pbmining not do it same

but if they do.. like all before done thats will be big boom
Of course PBmining and Luna are a scam. If A. They don't show you a picture of mining equipment, they are not mining.
B. They give out "non-variable" payments. I.E. you get $1 every hour like clockwork. They are not mining.
They are Ponzi schemes.
Even if they DO show you pictures of mining equipment... it could still be a Ponzi, or some other type of scam. 99% of these cloud mining are guaranteed partial or complete loss of "investment".