In the digital advertising business, this form of highly personalized marketing is being hailed as the latest breakthrough because it tries to show consumers the right ad at the right time. “The overwhelming response has been positive,” said Aaron Magness, senior director for brand marketing and business development at Zappos, a unit of Amazon.com. The parent company declined to say whether it also uses the ads.
Others, though, find it disturbing. When a recent Advertising Age column noted the phenomenon, several readers chimed in to voice their displeasure.
Bad as it was to be stalked by shoes, Ms. Matlin said that she felt even worse when she was hounded recently by ads for a dieting service she had used online. “They are still following me around, and it makes me feel fat,” she said.
With more consumers queasy about intrusions into their privacy, the technique is raising anew the threat of industry regulation. “Retargeting has helped turn on a light bulb for consumers,” said Jeff Chester, a privacy advocate and executive director of the Washington-based Center for Digital Democracy. “It illustrates that there is a commercial surveillance system in place online that is sweeping in scope and raises privacy and civil liberties issues, too.”