Most US internet users across all age groups are aware that businesses frequently listen to what they say online. According to a December 2012 study conducted by J.D. Power & Associates for NetBase, US internet users between the ages of 45 to 54 were most cognizant of this phenomenon, at 72% of respondents. Millennials between 18 to 24 years old were least likely to be aware of companies listening in, although still over three in five knew this went on. Read the rest at eMarketer.