Man.... You are just an ala carte dream killer.
Sorry, I love the idea of the dream. The math just doesn't work as "we" (consumers) want it to work. If "we" all were willing to pay more to get al-a-carte, the other players would have probably long-since delivered it. But "we"- the source of the money that fuels the whole model- want a big discount AND al-a-carte… and that's the problem.
How I get close to the al-a-carte dream is working with the established model. Many digital cable/satt boxes have an option to put favorite channels in a group. So my "15 channels I want to watch" can be my "favorites", hiding the other "185 channels I never watch". Visibly, this is an al-a-carte model where I see only the channels I want to see. Invisibly, there are still 185 other channels running commercials I'll never see to help pay for the overall model with other people's (subsidy) money.
To try to make it as economical as possible involves hopping from introductory offer to introductory offer as soon as contractually possible, working with the retention department just before defecting to see if the current provider wants to cut a deal to try to keep me.
For my situation, the current mix of "cord cutting" options doesn't work, mostly because I like sports programming and I want higher quality HD than many streaming sources will provide. Netflux, Hulu, etc is all fine but they don't cover all bases well enough yet for my wants. And- especially for sports programming- I think for them to eventually get there means big hikes in the monthly rates (as these "TV deals" tends to be important parts of holding up the whole pro sports revenue models).
So, again, love the concept. I just see the holes, that can't seem to be filled by the source of all of the revenue getting a fat discount. If I was any of the other players, I wouldn't want to take a big hit for that. And we all know Apple will want a nice big cut right off the top too.
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Stop right there. Why did you take off Apple's theoretical cut but not the cable companies' actual larger cut?
Because the cable company is going to get there's either way. If an Apple could eject them from the cableTV business, an Apple's solution entirely depends on the cable companies broadband pipes. Why are they going to roll over and not make up for those losses when they own those pipes?
Ah. Flim flam. Moving goalposts. What does a theoretical broadband price hike have to do with calculating HBOs revenue?
Ah, Flim Flam counter. I left the "theoretical broadband price" increase out of the prior post to keep the math behind the point simpler. Either way, I assume HBO gets paid what it wants to get paid (which will include taking the perceived risk of shifting to a new model). That can be at my guesses of $49/month or your guess whatever it is. However, I also expect the cable company to lose nothing on such a transition. So build it into the average price estimates per channel or build it into a broadband price increase.
Again, HBO doesn't need 4x-6x revenue to make a la carte viable. In fact, the 40% increase in revenue by keeping the same price and moving from a 50-50 to a 70-30 split is quite significant.
If all of the subscribers stay. If all of the subsidized subscribers are still subsidized by "HBO free offers with this package upgrade". Etc.
You believe what you want. I see NO scenario where the consumer masses can get the dream of al-a-carte for significant discounts to what we throw into the "as is" model. If you do, great. I'll hope the model you envision can be realized and then I'll enjoy the big discount to get everything I want.
TV might come down to feeding TVs in other rooms without having to rent a cable/satt descrambling box. It seems each box tends to have a $5-$15/month lease so if one can get what they want to watch via these "apps" through an 
