Gross means nothing. Net to owner is what matters. If you gross $1 million, but spend $950k, you are doing no better than a single route operator. And margins in this business don't improve much with 'economies of scale' in this business. Each route has some fixed costs no matter how many other routes you have. Sure, there is some efficiencies to be gained by having ground and HD routes in the same area.
One of my routes grossed a lot more than the others, but netted less due to expenses of a longer route and was a 12 hour a day route. One grossed less, was less costly to run, and was basically a nine hour route. Same thing is going to apply to comparing one ISP area to another. Gross is not the way to value the business. Maybe if you are selling widgets, use gross to determine value compared to another business selling the same widget.
Some of the economy of scale is lost when you suddenly need to expand but aren't netting the costs of expansion. At some point, you may need a full time mechanic, or a full time bookkeeper, that saves you $30k per year, but costs you $50k. It may take years to make the move worth it.