Lenny? I just do some mundane task while I am soaking their time.

These calls are using an anti-pattern of most people who are disinterested will hang up, but those who are interested will continue to talk to the person.

Their economic model depends on uninterested parties hanging up as quickly as possible. To disrupt their economics, take their call.

I know things are a bit different in the US and Canadia where the mobile/cell call receiver also pays for minutes. Here in the UK, and the rest of Europe, only the call initiator pays for the call. If you are calling from a land you will pay a higher rate to call a mobile (an 07 number).