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 OgilvyI don't know the rules of grammar... If you're trying to persuade people to do something, or buy something, it seems to me you should use their language, the language they use every day, the language in which they think. We try to write in the vernacular.
David OgilvyI avoid clients for whom advertising is only a marginal factor in their marketing mix. They have an awkward tendency to raid their advertising appropriations whenever they need cash for other purposes.
David OgilvyThe more story-appeal there is in the picture or in the photograph, the more people would look at your ad
David Ogilvy