In an effort to sell more iPhone 5s, Apple will start an in-store iPhone trade-in program this month, according to a new report from Bloomberg. Apple is running the program in conjunction with mobile phone distributor Brightstar Corp. According to the report, “Used iPhones collected in the U.S. will only be resold in emerging markets, where Apple’s share is lower and demand for cheap devices is greater.” By doing this, sales of the used…