It's called bundling. AMC knows that their AMC network is very popular. People love Breaking Bad & Mad Men & The Walking Dead. So AMC says to DirecTV: We will give you AMC and charge you $0.75 per subscriber. But wait there's more! If you want AMC (and you do because your customers demand it) then you also are required to carry WeTV and Sundance and IFC and pay us $0.25 per subscriber for each of those networks!
So now, with the $0.25 per subscriber subsidy, those networks have lower viewership numbers they need to hit to be profitable.
I chose DirecTV for my example because they got into a very public fight with AMC last summer and AMC was pulled from DirecTV. Basically DirecTV didn't want to pay as much as AMC was asking. In the end AMC won a pretty decisive victory and got almost everything they were asking for.
So now, with the $0.25 per subscriber subsidy, those networks have lower viewership numbers they need to hit to be profitable.
I chose DirecTV for my example because they got into a very public fight with AMC last summer and AMC was pulled from DirecTV. Basically DirecTV didn't want to pay as much as AMC was asking. In the end AMC won a pretty decisive victory and got almost everything they were asking for.