Business development is often mistakenly viewed as interchangeable with sales, but it is actually a marketing function. While business development professionals use some sales skills, the goals of business development - like brand placement, market expansion, and new user acquisition - are shared with marketing. The key difference is that business development aims to achieve these goals through partners in a scalable way, rather than direct sales to end customers. This allows companies to leverage existing partner sales teams and communities to reach new audiences, keeping their own business development teams small.