The traditional web design process is broken and doesn't allow for the changing needs of your buyer. Marketing has moved away from traditional advertising and is now about creating informative content. The buyer wants to be educated by brands, not pitched to. The businesses that are winning online are agile and constantly adapting to change. So why leave website design behind?
Growth-driven design moves away from top-heavy expenditure. It's a continuous website iteration process that enables change and drives growth.
Your sales and marketing efforts must map to changes on your website. You can really forward your strategy into tactics by putting website design at the core. The tricky bit is to ensure that this is backed by user research and content strategy.