1. Start with the geography you actually serve
Fort Pierce South is recorded as a CDP in St. Lucie County. the Census record does not establish that every resident is a potential client, that people search for legal services, or that your firm should target the entire county. A useful ROI view should keep those geographies distinct rather than combining them into one attractive total. If your service area includes Fort Pierce South and other places, the decision is whether those cohorts should be compared, not whether the Census estimate can stand in for marketing performance.
Recommended approach
Define the geographic labels your firm will use before reviewing performance. At minimum, keep Fort Pierce South separate from St. Lucie County and from any neighboring-city or metropolitan cohort that appears in the firm’s actual marketing data. If a geography is not measured, label it unavailable instead of estimating demand from population.
