Rule of thumb is always good, especially for ponzi 'cloud mining' scams like yours GG:
No proof of mining = Proof of no mining!
Ain't that so, GG/SS/RR?
Rule of thumb for all in the category of business.
Let it stand for itself for minimum of 2 years to even be looked at seriously, continue looking at their main thread on how they react to support and other related events.
If a bitcoin service/business proved itself with others during that time, then all there is to figure out to do a soft investing round.