GPS Marketers was hired by a firm that sold a product that helps soothe newborn babies to sleep faster with a gentle rumbling sound similar to what babies heard in the womb. The company had unsuccessfully marketed this noise machine product in a wide variety of magazines, including home décor, cooking, gardening, and wellness. When GPS came in, they convinced the company to narrow its target audience to parents of newborns and helped them successfully build their brand. 

Why was narrowing the focus a good decision?