The shoes that Julie Matlin recently saw on Zappos.com were kind of cute, or so she thought. But Ms. Matlin wasn’t ready to buy and left the site.
Then the shoes started to follow her everywhere she went online. An ad for those very shoes showed up on the blog TechCrunch. It popped up again on several other blogs and on Twitpic. It was as if Zappos had unleashed a persistent salesman who wouldn’t take no for an answer.
“For days or weeks, every site I went to seemed to be showing me ads for those shoes,” said Ms. Matlin, a mother of two from Montreal. “It is a pretty clever marketing tool. But it’s a little creepy, especially if you don’t know what’s going on.”
People have grown accustomed to being tracked online and shown ads for categories of products they have shown interest in, be it tennis or bank loans.
Increasingly, however, the ads tailored to them are for specific products that they have perused online. While the technique, which the ad industry calls personalized retargeting or remarketing, is not new, it is becoming more pervasive as companies like Google and Microsoft have entered the field. And retargeting has reached a level of precision that is leaving consumers with the palpable feeling that they are being watched as they roam the virtual aisles of online stores.