Seriously, it's highly productive. At least it was for me.. It's their interest to reach you, that's why they are calling you and not the other way around.

If I'm trying to write a tricky piece of code and you keep calling me, a) I will be annoyed and b) my mobile will go off, my email client will go off and the land line will be unplugged from the wall.

What are you going to do now? Put on a gorilla suit and come jump up and down on my desk? Learn some class.

To me that's, in general, not an acceptable information flow. It's a side channel that reveals information that I don't think people in general need to have.