Targeted ads allow websites to send more relevant content to website visitors and bring more revenue to publishers.
However, a recent study from the Pew Research Center revealed that of 22 news sites analyzed, only three - CNN, Yahoo and The New York Times - used high levels of ad targeting. Specifically, Yahoo switched ads 67 percent of the time, the Times 47 percent and CNN 45 percent.
CBS, USA Today and MSNBC displayed only moderate levels of ad targeting - between 29 and 40 percent of their ads were different across users - while FoxNews.com, WashingtonPost.com, Time.com and Newsweek.com didn't portray any targeting efforts.
Local internet marketers might have better luck on Facebook, as TechCrunch reports that the social network recently unveiled its Open Graph action spec targeting in beta form. This lets advertisers target users by their preferences and posts - i.e. what they listen to, where they travel and what they buy.
The move could potentially improve return-on-investment for Facebook ads and attract new classes of advertisers, or get existing ones to spend more.