I was reviewing my receipts from a recent business trip a few days ago, and was reconciling with my credit card statements to make sure I didn’t miss anything. As I looked across the charges – gas, dinner, hotels, retailers, rental cars, service providers – I began to contemplate and extrapolate how much my household spends with various businesses over the course of a year. The gas station two blocks from my house? $1,600 per year. iTunes? $600 (not counting all the gift cards....