Jamba Juice wants to bowl over customers with its newest breakfast product. The smoothie company just began sales of oatmeal in Chicago in advance of a national launch of the item next month. Jamba, with about 700 stores, earlier this year introduced a breakfast menu nationwide. With the oatmeal, it tries a product that’s proved successful for Starbucks. Since its September addition oatmeal has become one of the best-selling food items in the Starbucks system, the company said. Way to go, Jamba!