Even in virtual companies, someone still has to count the money. And there's a lot to be controlled and reconciled, as any accountant will tell you. Inventory, payables, receivables and cash all require scrutiny. And, as the transaction volume increases, so do the reconciliation challenges. A good example of this is credit card processing.
Sales are paid as they're booked, so there are no receivables.
But thousands of cash receipts might hit the bank as a single deposit amount each day. That's a challenge. And, because of various timing issues, some of them might not hit on the day they are booked by the accounting system. That can be a bigger challenge. In addition, there will be processing errors, returns, credits, fraud and more.