If you ever have the good fortune to create a great advertising campaign, you will soon see another agency steal it. This is irritating, but don't let it worry you; nobody has ever built a brand by imitating somebody else's advertising. ↗
I 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. ↗
I 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. ↗