Influencing others - truthfully

I occasionally get irate at TV commercials (ask my wife).  When I look across the landscape of our economy, it seems that 90% of all selling (from businesses, politicians and pulpits) involves lies, distortions, exaggerations, conflations, fine print and half-truths.  Or more kindly, persuasive emotional arguments based on faulty logic (my identity is tied to my car, clothes, [...]