> even if you have to run 20 km for each customer. That's, what, $10k a pop?

I don't know if we're still talking Africa or in general, but $10k doesn't get you anywhere near 20 km around me. I got municipal fiber recently, and our agency passes through the costs. On a 7 drop project of about 1 mile, aerial on existing poles, my share was $5k; plus I had to pay my own way to get conduit installed from the pole to my house, that was nearly $7k. Underground utilities are expensive!