One of the many ways I mindlessly overspent money in the past was buying two books online instead of one, in order to get the total up to $25 so I could get free shipping. And even buying the first book was almost always done on impulse. I’d hear about something online or from a friend, jump on the website, then find something else that sounded good and add it to my cart, all to get that unpleasant shipping and handling fee down to $0. I did this at least once a month for probably close to a decade.

