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What service? And how to identify scam from a reliable service?

I checked Wattum.io, so they are legal and they provide a quite lucrative interest rate for a long period of time.
Their mining centers located in warehouses in Canada.

Before choosing your mining service read this criteria to help you spot a cloud mining scam:
No public bitcoin mining address / no user selectable pool
No endorsement from any asic miner vendor
Open ended IPO / fractional reverse mining risk
No exit strategy from cloud mining website
Cloud mining companies that offer “guaranteed profit”