As a nation of shoppers—70% of gross domestic product comes from consumer spending—we probably buy too much stuff. But look on the bright side: All that shopping could make us better stock pickers. Even investing icon Peter Lynch took note of the advantages we can gain from watching spending trends around us—and famously invested in a pantyhose company because his wife liked its product. Simply put we just favor the retailers we love over those we hate a concept you can readily extend to consumer companies beyond the mall to include those that sell us stuff like cars telephone ...