We're talking about different things, I think.

What the OP is describing is something like this:

Buy 1: Each one costs $10
Buy 2: Each one costs $4 (total of $8)

Why would anyone buy only 1, if buying 2 costs $2 less? So, everyone should buy 2. And throw away the extra.

But, if everyone buys 2 and throws one away, how does this benefit the company?

This is different from the following, which I think is what YOU are describing:

Buy 1: Each one costs $10
Buy 2: Each one costs $8 (total of $18)

In this case, no one would buy 2 just to throw away the second one. Why? Because here, you'd be wasting $8.

See the difference? With the OP's case, it costs less TOTAL (not just per service) to buy multiple. And she's "throwing away" the cable.

I think the reason we're looking at this different has to do with the numbers. Unless you tell me that it costs on of your customers less TOTAL to take multiple services...

Or am I confused?