Skin serums that cost $200 a jar won’t cut it in China…nor, for that matter, will $10 shampoos. No wonder why Procter & Gamble is trying to understand the needs of the very poor in developing markets. That’s why the company launched its $2-a-day program in 2009. Many consumers in these areas make do on annual salaries of less than $200, and yet, they are P&G’s target consumers in many developing markets. That explains why P&G employees spent weeks in r...