I have noticed that many people walk into a store and see, "buy one get one free" and immediately pick it up for purchase. Have you ever walked into a strore and seen all the things you don't need, but because it is cheap you want to buy it?
Almost everyone of us has. Now internet hunting is where it hits the worst. Have you ever gotten on KSL just to see what is free or $1? I know many people who have.
These impulse searches are the reason we have showes about hoarding and how many people are shopaholics. Watch your purchases and make sure its worth it. You never know how much money you are spending on something you don't really need.