I would like to see some studies on the effectiveness of the various targeting criteria. Sometimes i think marketers obsess on targeting criteria that may not b

I would like to see some studies on the effectiveness of the various targeting criteria. Sometimes i think marketers obsess on targeting criteria that may not be so effective, missing other psychological effects. For example, i thought google's idea of showing you the same ad across websites to make a lasting impression was a no-brainer, yet it was missing for years. Also what about other factors such as time-of-day, or recently clicked ads?