Like many folks, i DO NOT answer the calls if i don't know the caller. That's why they invented voice mail and texting.
There is a powerful urge to answer the phone that lives in most of us, the urge to communicate, the fear of missing something or being left out.
On the little news clip announcing the new program they showed a 30 something women starring at her phone, in emotional distress, wanting to answer but knowing she shouldn't.
I repeat myself when i say, advertising people and lawyers know the truth about being human, like we all do except, they know how and are willing to leverage that knowledge.