A. "Free" offers. When the price of something is said to be zero, it blinds us. We get so excited, we fail to realize that we'll end up paying in some way.
Question: For instance?
A. When I bought a car a few years ago, I debated between two choices. One was less practical but had a special deal going for it: free oil changes for three years. This sealed the decision for me. Later I realized that since I don't drive much, it was only $150 to $200 in savings. And in the end I was left with a less practical car.
The book "Predictably Irrational: The Hidden Forces That Shape Our Decisions."