After listening to what someone said and then saying to them "Tell me more.", you are redirecting them to trust their spontaneity rather than shutting them down in their certainty. This inspires creativity when something is needed more than what is known by what was said.  We tend to only respond to what is said or not said oftentimes unknowingly creating the sense of argument rather than being heard. "Tell me more." is saying yes to what can be discovered rather than aquiescence to a possible bad idea or viewpoint.