We live in a consumer society. Household spending accounts for a bigger share of the country's total economic output than all other activities put together. The world's biggest company, Walmart, operates more than 10,000 stores in twenty-six countries and employs 2.2 million people. Shopping permeates our culture. The concept of branding is ubiquitous, to the point that individuals are urged to develop their own "personal brand." But why...