With consumers doing holiday shopping later every year, savvy direct merchants are figuring out ways to extend their season to compete with bricks-and-mortar etailers. For example, year-over-year sales were flat for several specialty food catalogers and Internet retailers at the start of December. But thanks to an additional mailing that month and intensified online marketing activities, they achieved an average sales gain of 16 percent versus the prior year, said Tony Cox, president of 5th Food Group and Catalog Solutions, a catalog marketing firm that works exclusively in the specialty food industry. By being able to adjust our promotions with pay-per-click advertising and electronic gift cards, it helped us extend the season, Mr. Cox said, and that's what [produced the sales gain] as much as anything else. After a few years of testing PPC advertising, these specialty food merchants made a larger spending commitment to the stra