What is most important to an effective software demo?

I'm always curious what makes a compelling argument.  I learned much from valuable feedback from colleagues today, in fact.  

I turn to the legal world and how lawyers navigate complex rules and laws to communicate to jurors, people from varied background and knowledge on forensics, dna, technical evidnece and the legal framework.  Great Lawyers use a simplistic dialogue, painting a picture of how, why and who - trial lawyers often use the technical and evidence-driven process but what is remembered is when the glove doesn't fit, when you cant handle the truth, when a breakthrough or moment defines the result. 

Simplicity seems to sell better.  Add to that the requirement to know your audience and to be credible and consistent and you've got a good start. 

I have gone with a variety of methods to communicate value-based messages and benefit-rich presentations to a variety of audiences.  None in particular works as a "rule of thumb"  however using a story that does not conflict with your audience that still connects them to the solution through dialogue and interactive and informal discussion is often more valuable long-term than product-heavy and technical specs. 

The engagement cycle should be communicated, agenda laid out in advance, then expectations and "homework" should go both directions or in some cases with multiple audiences involved in a complex sale.  After you've initiated the engagement process, continue to communicate what your prospects need to do to fully realize the value and include all the key stakeholders that should be involved.  Jurors don't get a day off or else they may miss the key deciding ingredient in making their decision.  Pay as much care and attention to your audience as the message.  In deliberation, certain people who may not be as senior may sway the group.   

Happy Marketing.