I would suggest looking at Comcast's subscriber numbers they release with their quarterly earnings. They are still gaining subscribers. I'm not sure they have recovered to pre-recession levels yet. Employment & housing have such a huge impact on the cable industry it's hard to decouple the data. You could argue the subscriber drops of previous years were due to IP video but now that the numbers are on the rebound that seems unlikely unless people switched to IP video exclusively and found it to be inadequate. It's also important to look at Comcast (and others) own IP video solutions which are not talked about a lot but may fill the void that would otherwise send customers into IP-only solutions. If you have Comcast and you want to watch TV on your iPad the easiest way is to just use the XFINITY TV app. The cable MSOs were very slow to take IP video seriously but, IMO, they are in much better shape now. I'm sure HBO is aware of this too. They are betting that bundled linear/IP services are going to be the way most customers consume media.
But it's worse than that. The number of households in the US has increased by about 1.1% per year for the past 20 years. If Comcast and HBO aren't growing their raw US subscriber numbers by at least 1.1% per year - probably more given that they mainly serve urban markets that typically outpace rural growth - then they're falling behind household growth.
