If you want to know what the Target Effect is, just think back to that old Lays potato chip commercial that highlighted the fact that nobody could eat just one. Scale that up to big-box retail and what you have is the Target Effect.
When you go to Target, or any store like target for that matter, you may have the intention to purchase just one or two items. But in reality, you end up driving away with no less than $ 100 worth of shopping. If this sounds like you, just know that you are far from alone.