The theory is that most of the cost of your cable package is going back to the networks. So from a technology side the incremental cost to add channels is zero

The theory is that most of the cost of your cable package is going back to the networks. So from a technology side the incremental cost to add channels is zero but from the business side the cable operator still has to pay for each additional channel they put on their service. If they put fewer channels in the package they sell you then they could sell you the package for less money.