for the record, you can be a legit company (startup or not) without necessarily requiring a real office, virtual offices work well for hundreds of thousands of businesses, and not every virtual office-based office is automatically a scam, which is especially true for many hosting companies that are acting as resellers.

That being said, like was said, colo-costs will be a significant factor given the Thash/sec rate advertised by cloudhashing.com, which would support the assumption that  they should have supporting information to back up their claims (e.g. contracts, billing, invoices etc) that can be checked by potential customers, to ensure that their money is actually being used for these purposes. So far, the whole thing seems to lack in transparency unfortunately. If such information could be provided, based on 3rd party companies that are actually real, customers could make up their own minds.