One of the reasons why we are extremely successful in the US Entry Waiver industry is that I am a heavily decorated former American law enforcement officer, former law enforcement trainer, and former U.S. Govt employee. Specifically, I left my last federal agency the year that they changed everything over to the new name of Homeland Security.
This foundation and having the academics, educational credentials, street smarts, being a former American law enforcement trainer/instructor, former American federal employee, former American Soldier & Airman, and more, easily facilitates the understanding of these waiver applications.
Specifically, we previously enforced the same laws and procedures on people (including Canadians) in the USA that the border uses when adjudicating a waiver case. Thus there is a familiarity when us entry waiver applicants come in.