Retail had an article presenting research on how many people think certain types of personalization are creepy and asking whether the number of people thinking these activities are creepy will decrease in the future:

While many consumers are comfortable sharing information in return for benefits, that does not mean they like companies using the information in ways that are creepy. For example, Amazon may give suggestions about what other shoppers have purchased while you are online but that is not the same as computer screen suggesting accessories while you are in the dressing room trying on clothes. Finding the line between helpful and too invasive is critical for success.