The last time you used your zip code, you were most likely entering your address into a website to make a purchase, finding a store near your home or office, or filling out some other online form. You likely found the answer you were looking for and didn't stop to think further about that five-digit code you'd just typed out.However, lots of companies, marketers and data analysts spend hours looking at zip codes. They are deciding how to use data tied to those zip codes to understand trends, run...