The Three-Mile Map: press kit
On October 15, 2026, Isoline Growth ran 7,056 Google Maps searches for 138 Charlotte-area HVAC, plumbing, pest control and garage door companies, weighted every result by where people live, and checked what ChatGPT, Gemini and Google's AI Overviews recommend. Everything below may be quoted or republished with credit.
Five findings to quote
- 70% to 1%
Counted by residents, Google's top-3 visibility for Charlotte home service companies falls from 70% near the shop to about 1% at 6.7 miles.
- 3%
Outside its own neighborhood, the typical Charlotte home service company ranks in Google's top 3 for about 3% of residents within 10 miles.
- Median 0
Companies with under 50 Google reviews had a median of zero top-3 spots. Above about 150 reviews, review count showed no relationship with reach.
- 1,338 companies
1,338 companies held a top-3 Google Maps spot somewhere in our searches. National brands and franchises we could identify held about 6% of those spots.
- 27 of 53
ChatGPT named 27 of the 53 local companies we checked, and Gemini named 31. Google's AI Overviews returned sources in only 16 of the 53 checks and named 2. ChatGPT cited Thumbtack, Angi and HomeAdvisor among its sources every time.
Eight more findings, with charts and 95% ranges, are in the full study.
Charts
Each chart carries the Isoline credit. Landscape files are 1200 × 630; square files suit social posts.
Download the full report (PDF, 2 MB)
Method in brief
- Companies
- 138 Charlotte-area HVAC, plumbing, pest control and garage door companies (144 company-and-search pairs)
- Searches
- 7,056 Google Maps searches on Oct 15, 2026, about 7 to 11:10am Eastern: hvac repair, plumber, pest control, garage door repair
- Grid
- 7 × 7 points per company, 10 miles each way from the shop, about 3.3 miles apart; top 20 results recorded at each
- Weighting
- Each point weighted by residents in its cell, from 2020 Census block groups; 95% ranges from 2,000 bootstrap resamples
- AI check
- 53 companies checked once on ChatGPT, Gemini and Google AI Overviews
- Limits
- One metro, one morning, one search term per company; not a random sample of Charlotte businesses. Full limitations are in the study.
Rank data collected with Local Falcon. Map data © OpenStreetMap contributors.
Credit line
Source: The Three-Mile Map, Isoline Growth, October 2026 (www.isolinegrowth.com/research/three-mile-map/)
The findings and charts are published under a CC BY 4.0 license: reuse them with credit and, where your format allows, a link to the study.
Data and local cuts
Reporters can request the anonymized data, or a cut by trade or by part of the metro (for example south Charlotte and Ballantyne, University City, or Union County and Matthews). Every cut reports patterns, with individual companies kept anonymous.
About the author
Neil is the founder of Isoline Growth. The firm does marketing for HVAC, plumbing, pest control and garage door companies and publishes the data behind it. He has managed more than $1 billion in advertising across his career, the largest share at Allstate, where he built the in-house digital media team. He holds a Wharton MBA.
He co-authored "Cross-Funnel Synergistic Effects in Media" in the Journal of Advertising Research (2025) and holds an MBA from Wharton. Full bio.
Press contact
Neil, founder · [email protected] · (980) 580-6715