Where I currently live, there was a local, minority ownwd cable company that had an exclusive franchise with the county. The company was bought by a much larger company that was neither local nor minority owned, so the exclusivity clauses of the franchise automatically expiired. Since then, the only "compettition" to deploy in our area has been the phone company with their DSL service. For maybe a year, the 2 companies were actually competing - because a lot of people switched over because of the promotional rates offered. The cable company put out some promotional rates, too. Then the cable company deployed some low cost equipment upgrades in their local data center and neighborhood and pushed out firmware updates to the subscriber modems, doubling the data rate. Very quickly, all the customers who wanted the higher data rate switched back, but the phone company did not and still hasn't upgraded its service, claiming it would have to upgrade the "last mile" drops in order to increase data rate (they even said that if a subscriber was willing to pay them $300 per hour for technician time, they would upgrade those customers who chose to do so). So, effectly, the 2 companies have apportioned the market into a "high" and "low" segments. Since the cable company does offer low data rate plans (and the phone company offers high rate to hose willing to pay for last mile upgrades), there is no way to prove collusion, even if they did collude.
I am accross the street from a block that is served by 2 cable companies, so I have asked the other cable company why they have not extended in to my block, they cited the high cost of deploying new infrastructure. They also said that if I had neighbor in the block they did serve, they'd be happy to provide "second unit" service to that neighbor's house, billed to me, but I would have to arrange my own means to bridge the service to my house (easily done using an extra wifi router and 2 directional 2.4 GHz antennae. Unfortunately, that neioghbor has since moved out so I no longer have that option). Presumably, they would not have offered this sneaky way to get service to me if they weren't confident there was no longer an exclusitivity provision "protecting" the incumbant cable company.