They're probably a pretty smart person. This industry requires a certain amount of "smarts" for initial admission.
They probably possess an out-going, people oriented personality - and genuinely like most people.
They most likely have strong verbal skills. Most sales people do. Advisors are great talkers and can engage all types of people in conversation.
We'll assume that they have faith in their ability to make their own success. People in a commission- only position have to possess this personality trait.