After paying off $30,000 of debt in two years, Cait Flanders found herself spending too much because she never addressed why she got into debt in the first place. She went on a two-year shopping hiatus and discovered her spending was more emotional than anything else. In her book, "The Year of Less" she chronicles her journey and teaches us to hack our shopping habits for the better. In Mailbag, short-term and long-term investment decisions and lowering your credit card's interest rate.