Yes. And No.

It entirely depends on how you define ‘great’ advertising.

If you simply mean advertising that sells then the answer is no, not necessarily. And I’m not just talking about by the book, quant tested FMCG schlock here. If you look at the world of fashion advertising there is a distinct absence of what we in the advertising would regard as a ‘big idea’ ( or any idea at all really ). Yet it works.

If, however, you define ‘great’ advertising as not just selling, but doing so in a cost effective manner – or as in some way adding to the sum of mankind’s existence then you’d have to say a big idea really rather helps.
It inveigles its way into people’s minds and can often stay there for years. Useful whether you are a brute marketing pragmatist after cost efficiency, or a believer in the power of brands for good seeking a salve for your professional conscience.