I don't agree with this. I had a great salary negotiation, over the phone. It was all prepared, i had answers ready for me for the negotiation, prepared by my stepsister (who recently had a mission at a recruitment firm), she listened to the interviewer/manager, pointed me to the correct idea for negotiating, and i landed +60% of my old salary (loosing two vacation weeks, i only have 8 left, but still). Nothing to do with being a good communicator.