According to David Aaker, the vice chairman of Prophet and the author of Brand Relevance: Making Competitors Irrelevant, a serious threat facing most brands in dynamic markets is the loss of relevance because the category or subcategory they are serving is declining. Customers are no longer buying what the brand is perceived to make. New categories or subcategories emerge as competitors’ innovations create “must haves.” This dynamic can happen even if the brand is strong; customers are loyal; and the offering has never been better, thanks to incremental innovations.