Never stop testing, and your advertising will never stop improving. Testing was used in advertising decades ago. The internet has made testing so easy that every online marketer can use it to improve advertising results. Google content experiment is a free tool for you to do split testing.
David OgilvyIt's the lack of ambition that cripples most people, and makes them so pedestrian in the advertising/creative business
David OgilvyI had a friend who was the King's surgeon in England. One day I asked him what makes a great surgeon. He replied, "What distinguishes a great surgeon is his knowledge. He knows more than other surgeons. During an operation he finds something which he wasn't expecting, recognizes it and knows what to do about it." It's the same thing with advertising people. The good ones know more. How do you get to know more? By reading books about advertising. By picking the brains of people who know more than you do. From the Magic Lanterns. And from experience.
David Ogilvy