• by Wayne Friedman , Staff Writer, June 30, 2015

Big media companies that control TV networks will continue to be strong for the next half a decade -- thanks to affiliate revenue. But what happens then?

Revenue from those company’s core media businesses -- advertising, affiliate fees, and TV program sales -- will continue to rise on a compounded annual growth rate of 5% -- a bit less than the 6% hike over the past five years, 2010 to 2015.

Looking at companies including, 21st Century Fox, Viacom, AMC Networks, Scripps Networks, Walt Disney, Discovery Communications, and Time Warner, one estimate from MoffettNathanson projects a 1% decline in subscribers to those networks, with a 8% rise in the subscriber pricing.

Viacom, which has been through a rocky stretch, looks to get the worse of it -- a 2% decline in subscriber numbers over the next five years. But it’ll have company: Disney, Discovery and Time Warner will also each witness a pullback of 1%.

Walt Disney -- in large part due to ESPN -- will continue to be tops in affiliate revenue for many years --  $9.9 billion annually projected for this year, with 21st Century Fox the next biggest at $8.1 billion. MoffettNathanson projects Fox will overtake Disney in 2020.

Sounds great? Not exactly.

Big media companies may crow about how their diversifying revenue sources -- like affiliate/retransmission revenues -- continue to help even out the ups and down of the national TV advertising market. But down the line, with the population aging and millennials not afraid to explore other options, things will change.

Much of this will rest with pay TV providers -- cable, satellite, and telco  -- who will continue to see a steady decline in subscribers, around 1% per year. And then -- as some expect -- five years down that line that drip may turn into a steady leak.

So if you are mature TV network, you might be asking this question: Will pay TV providers continue to fork over ever-higher per-subscriber wholesale pricing for broadcast and cable networks, when those networks will -- no doubt -- continue to get declining viewership?