One of the widely debated issues in developing marketing programs that target certain age groups is how much consumers change over time. Some marketers maintain that age differences are critical and that the needs and wants of a 25-year-old in 2002 are not that different from those of a 25-year-old in 1972. Others dispute that contention and argue that cohort and generational effects are critical and that marketing programs must therefore suit the times.
Age differences are fundamentally more important than cohort effects versus cohort effects can dominate age differences.