So his bottom line is $50&#x2F;month per customer for a constant 10 mbps. To put that into perspective, the operating profit margin of wireline ISPs is 5-20%. The low-end of that scale is for traditional phone&#x2F;DSL&#x2F;fiber. Assuming an average subscription of ~$100&#x2F;month, that bandwidth is coming out of an operating profit of $5-20&#x2F;month.<p>Obviously the cost of bandwidth is a lot less than $50&#x2F;month. But even at 1&#x2F;10th that figure, it&#x27;s a big chunk of the variable expense of the service.