Marketers at Kraft Foods hope Doug's misadventures will whet consumer appetites for the company's entry into the crowded US peanut butter market. In what may be the most overdue brand extension in history, Kraft is using the 100-year-old Planters name to speed growth of its mature grocery business. Kraft is targeting adults, who consume two-thirds of the $1.8 billion of peanut butter sold in the US each year, says Triona Schmelter, Planters' senior director of marketing. Kraft hadn't invested much in Planters, making it easier for private-label snacks and offerings from faster-growing rival Diamond Foods to feast on its business. From 2005 to 2010, Planters sales at US stores excluding those of Wal-Mart Stores tumbled 12%, according to researcher SymphonyIRI Group. While Planters' brand recognition and Peanut Butter Doug's viral antics on the Web and on Facebook helped get the new line off the ground, sustaining growth will be tough, figures Ken Harris, an analyst at researcher Kantar Retail.