Drug-receptor interactions

Hey there,

I'm a Biology student doing a Pharmacology module and I'm not too sure where to post this question but thought the Chemistry forum fitted it the best.

What does non-specific binding of a ligand show? That is besides specific binding as specific binding is (total bound-non-specific).

The question in my assignment is :
What does the non-specific binding tell you about epibatidine (that's the ligand). And I can't think of anything more than it tells you than the specific binding of the ligand to the receptor. Or is that the only thing. It just sounds so blindingly obvious.