News broke late Wednesday that Comcast, parent of CNBC owner NBCUniversal, agreed to buy TWC for about $45 billion or $159 a share. That was just shy of the $160 that TWC said it wanted after cable rival Charter Communications made a bid of $132.50 in January.
The deal talks got serious about a week ago, according to a person familiar with the matter, who added that Charter had approached Comcast about dividing up TWC shortly after making its public bid in January. Comcast hadn't come close to making an offer before that time, though it had been in talks with TWC in the fall, the person said.
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No doubt, there are questions about whether regulators will allow Comcast to combine the nation's number one and two cable companies and control 30 million subscribers. Yet the companies have no geographic overlap, giving Comcast a strong argument that the deal won't hurt consumers.
Assuming the deal gets a green light from regulators, the most obvious loser is Charter, whose shares fell 6 percent Thursday morning. Charter didn't respond immediately to a request for comment.
Charter shares had rallied about 20 percent since last June when investors learned of Charter's interest in TWC. Much of that gain was based on the expected cost savings Charter would enjoy if it had made a deal.
Unfortunately, cost savings probably aren't enough to justify a bid above Comcast's. Indeed, Comcast's bid implies an enterprise value, including debt, of 8.3 times consensus 2014 earnings before interest, taxes, depreciation, and amortization. That's a roughly $16 billion premium to TWC's $28 billion market capitalization last June before deal talks sufaced.
By contrast, Comcast says it expects $1.5 billion in operational cost savings from a merger with TWC. Assuming a tax rate of 35 percent, and put on a multiple of 10 times, those tax savings are worth about $10 billion. Comcast shares fell 4 percent Thursday in midday trade.
What can Charter do? The good news is that Charter is already on track to earn bigger profits by selling customers more digital services. But there aren't many large acquisition targets other than TWC. That also raises questions about John Malone's Liberty Media, which has acquired a 27 percent stake in Charter with the apparent intent of using the company to consolidate the U.S. cable industry.
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A larger Comcast is also troubling for television programmers, which are constantly in tough negotiations with cable and satellite companies over carriage fees. More customers probably gives Comcast leverage when those talks stall.
That's especially worrying for small programmers who only command a small number of viewers. But large programmers can also run into trouble.
Consider Viacom, which often sells its programming in a bundle of over 20 channels to cable companies. In 2012, Viacom got into a public spat with DirecTV because the satellite provider didn't want to carry some of the lesser-watched networks. When the companies couldn't reach a deal, Viacom channels became unavailable to DirecTV's roughly 20 million customers for several days.
Comcast may also have grounds to argue that it pays too much for some larger channels that aren't performing well. Nickelodeon averaged 2 million viewers in 2013, down 14 percent from 2.3 million in 2012, according to Nielsen. Yet Nickelodeon's carriage fees from all of its cable and satellite distributors rose 11 percent to $729 million last year from $657 million the year before, according to SNL Financial.
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Viacom isn't alone. Time Warner, which also sells a large bundle of channels to Comcast has had ratings troubles at its CNN cable news channel. Yet carriage fees for CNN have continued to rise, up 5 percent to $719 million in 2013.
Broadcast networks could also come under a bit more pressure. CBS, which has usually been the nation's top network in the last several years, collects so-called retransmission fees from cable companies in exchange for the right to distribute the channel. On Wednesday, CBS said it aimed to collect $2 billion in such high-margin fees by 2020. That target came after a previous goal of reaching $1 billion by 2017.
CBS seems unfazed. In a CNBC TV interview Thursday, CEO Leslie Moonves said "at the end of the day, if you have the right content you're always going to have the power."
One company that's probably safer than most is Disney, whose ESPN network carries large amounts of exclusive sports content that people prefer to watch live. Such content has proven so important to viewers that ESPN has been able to achieve impressive fee increases over the years.
Beyond traditional television, Comcast may gain leverage over companies like Netflix, which depends on Comcast to provide high-speed broadband service. Under current rules, Netflix can use large amounts of bandwidth to serve its customers. But if laws change, Comcast would likely have the easiest time squeezing money out of Netflix.
The upshot is that size matters in the cable business. But programmers in particular also know how to play that game. It shouldn't come as a surprise if a pair of them strike back at Comcast with a deal of their own.
—By CNBC's John Jannarone. Follow him on Twitter @jannarone