Good design understands why every pixel is in the design. The designer knows how every element is directly serving the user in each instance. Automatic design (“every page needs breadcrumbs at the top, whether we have evidence it helps or not”) rarely accomplishes this.
— In a rebuttal article, Jared Spool questions the addition of breadcrumbs to websites by default, and suggests in many cases there may be better solutions. His reasoning is solid: most breadcrumb implementations don’t expose the sibling elements at each level of navigation, and often the terminology used in a site’s hierarchy is at odds with a user’s expectations of where to find content. Worth a read.