1. Start with Johnston’s actual service footprint
Johnston is a municipality in Polk County, Iowa. The 2020–2024 ACS five-year population estimate for Johnston city is 24,384, with a margin of error of 37. That is geographic and eligibility context, not proof of legal demand, search volume, competition or lead volume. The important attribution question is therefore not how large Johnston is. It is whether your firm can distinguish inquiries associated with Johnston from inquiries associated with the wider Polk County service area and other places your practice serves.
Recommended approach
Define the geographic fields you want to inspect before reviewing performance. Keep Johnston city, Polk County and any broader service area as separate values. Ask whether the intake record captures location consistently, whether a location is available by the prospective client or selected by staff, and how matters outside the intended footprint are handled. This prevents a city-level question from being answered with county-level or statewide data.
