The results of a major series of eye-opening studies about targeted online marketing were recently published, with significant implications for advertisers. Researchers at the Harvard Business School, the University of Virginia's Darden School of Business, and IESE Business School conducted a series of experiments as part of a joint study in which they presented test subjects with a variety of online advertisements and revealed under the hood details about why they received those particular ads.

Researchers found that people were less likely to click on content when they learned marketers had used third-party data or made inferences about their tastes drawn from information they hadn't provided. However, test subjects embraced ads based on their previous activity on a site. In another experiment, participants viewed a promotion that was served to them using third-party information, along with a prompt alerting them that they could select ad blocking preferences. Their purchase interest was just as high as another group who viewed the ad without any disclosures about where the content came from.