Three decades ago Costco created Kirkland Signature, the store brand it now uses to sell everything from paper towels to fresh sushi. At the time it was counterintuitive. Successful retailers, including Sears and grocer Safeway, used individual store brands to offer different types of products, often at the lowest price possible. Instead Costco consolidated its store brands into one brand, Kirkland Signature. The warehouse retailer aimed to make clear to shoppers and its own employees that Kirkl