Wasn't the whole conversation stopper thing started with the Reasoning book?
A few years after I left the Borg I applied for a job as a telemarketer. When I was interviewing, the manager asked if I would be prepared to get rejected without taking it personally. I said no problem, I used to be a door-knocking JW! I nearly flipped when I got to my training class and they gave me a booklet filled with the exact same concept: how to keep going when the poor schmuck on the other end of the line says he's not interested, etc. Maybe the Dubs should look into telemarketing instead of all those office cleaning businesses. They've certainly got the experience for it!