Never stop testing, and your advertising will never stop improving.
Lazy and superficial men and women do not produce superior work.
Don't count the people that you reach, reach the people who count
Tell the truth, but make the truth fascinating.
No sale, no commission. No commission, no eat. That made an impression on me.
Nowadays it is the fashion to pretend that no single individual is ever responsible for a successful advertising campaign. This emphasis on "teamwork" is bunkum - a conspiracy of the mediocre majority.