I'm sure the fact that they pay near zero in office rent/leases helps such companies with cash flow. You're also likely to get more productivity form employees

I'm sure the fact that they pay near zero in office rent/leases helps such companies with cash flow. You're also likely to get more productivity form employees that don't have to spend 2-3 hours per day traveling. I found myself working a full 8-9 hours when working from home, whereas if I was traveling to the office I'd be looking to duck out after 6-7 hours. The 3pm slump is a drag and I personally dread the commute home. Those few extra hours mean that I can squeeze out more code.