I think from a customer service standpoint, having an ala carte menu would be a nightmare for cable/satellite companies. They would have to hire more workers to please more consumers, most of whom would change their minds next month. This is why they probably won’t do it, IMO.
how do they do pay per view or pay channels for movies? The technology is there , they can see what you're watching and for how long. If they really wanted to know what the "ratings" were then the cable box would give them really good data. Fitted with motion detectors, could even sense if someone was watching or if more than one person was watching.
They could even give people a break by getting data on volunteer families that would allow the technology to make them "Nielson" families.