Does e-mail marketing work? Yes! In fact, 39 percent of online shoppers said they bought something through a catalog after receiving e-mail, according to a study commissioned by DoubleClick. Indeed, e-mail marketing has become a critical tool in the marketer’s drive for product-specific sales and to move clearance merchandise. Other uses include: encouraging customers to visit retail stores and to shop from catalogs; rapidly collecting inexpensive market research; providing service updates; and supporting partner sales. Following are 20 tips that can help you effectively and profitably use the e-mail medium in your multichannel marketing plan. 1. Use e-mail to alert customers that a new