You own and build your own infrastructure. A figure I saw was - $25k for infrastructure to serve 3000 customers, $50 per month flat rate. The money would definitely flow.
The opportunity here is that the cable companies are too busy upgrading existing nets to bother with small-timing like this. The opportunity won't last long, but the window is open NOW.
You could get the business going with as little as $50k in cash - $100k would be better. I'm so certain this would work I'd quit my existing job to help develop it.