I would bet there are also a bunch of fixed costs (per unit area of land that is served by the grid, let's say) that don't drop if you lose customers. You've g

I would bet there are also a bunch of fixed costs (per unit area of land that is served by the grid, let's say) that don't drop if you lose customers. You've got to have utility poles, trim trees away from power lines, etc. regardless of whether you serve 100% or 25% of the customers in that area. If you lose a lot of customers, you will have to raise prices on the ones that remain. If you're competing against something that already took away some of your customers, then raising prices could have a snowball effect and cause you to lose more.