I don't mind the GD calls.
When they call to remind me about expiring domains I view it;
a) as good customer service
b) as good customer retention efforts on their part
Any "up-sells" are usually "soft sells" presented as suggestions.
Plain and simple, it's good marketing to your existing client base.
Program owners and service providers can learn much from the GD approach. If you're a "mud on the wall" porn slinger then this method of marketing is probably above your head.
Being proactive? - usually wins
Being reactive? - minimal results