It used to be in-between uncommon and common.. maybe a few times per year? Probably more common for people working in locations requiring an employee to find a replacement of they needed a shift off, and therefor consulting a list of numbers they dial manually. Even if we did save numbers, our world was smaller and we might save someone as Sue. But then we meet another Sue at a party at Doug's house, so we save them as Sue from Doug's. But then the first Sue starts dating Doug.