Call this the reason Verizon has made New York City and the surrounding suburbs a key "must win" market for Fios and is starting to crank up the PR, Advertising and sales efforts.
Cablevision is one of the largest cable operators in the country, but focuses only on the New York area, unlike the others who are much more widely dispersed. That allows them to focus marketing and promotion and gain market share and penetration levels more quickly and more efficiently, even if NY is the most expensive market in the USA overall.
By having 2 million customers using their VoIP service, with more being added every day, they are cutting deeply in to the monthly revenues of mostly Verizon, and since that takes money away from services that ran over already paid for installations from years gone by, Verizon is losing pure profit.
Two million is a big number. But its also very indicative of the massive levels of success which well structured marketing in a confined area can bring to a cable MSO. In the case of Cablevision, they have proven that there is a market, and that the market is ready, willing and switchable.
Now let's connect a few dots. Jonathan Greene has a very good summary of Cablevisions' plan to create a wireless cloud that provides on the go Internet access using WiFi today and likely other technologies in the future.
This all leads to a WiFi phone service likely coming to Cablevision soon, which is why Verizon Fios and Verizon Wireless are already being co-marketed. Candidly, if I was a Verizon I'd worry less about the business they're bound to lose to Cablevision and focus more on winning customers where Cablevision isn't.