The ideal answer is both. With its style, it conveys your identity and captures the attention of your targeted audience. With its substance, it makes essential points and motivates that audience. Well-informed marketers see to it that both their style and substance are obvious but that their product or service always has the starring role in their marketing. We've all had the experience of viewing a TV spot or reading an ad and wondering what the heck they were talking about, so you know what I'm getting at.
Many websites are more confusing than they are enlightening.
In the early days of marketing, nobody needed special effects. When Harley Procter and his cousin, James Gamble, churned their soap too long and it floated, they came out and said Ivory is the soap that floats. People knew exactly what they meant. But now the creative revolution is upon us. In the name of creativity rather than the less glamorous but more accurate name of selling, billions of dollars are being wasted each year.