Even as retailers debate the efficacy of social-media marketing on Facebook and Twitter, they have no doubts about the power of a decades-old technology to drive sales. The killer app is called e-mail.
Retailers as disparate as Williams-Sonoma Inc. and Home Depot Inc. have become much better at tailoring e-mails to specific customers rather than the one-size-fits-all blasts that once dominated this type of marketing. Measured by sales per dollar spent, e-mail outperforms social-media advertising three to one, according to the Direct Marketing Association, a trade group founded to provide accurate marketing data. That explains why retailers will send 19 percent more e-mails this year.