Geofence Ads for Local Services: Radius, Frequency Caps, and Real Attribution

Geofence advertising looks simple: draw a circle around a competitor's office or a geographic area, show ads to everyone inside it. In practice, it's a way to burn budget fast if you don't understand radius decay, frequency fatigue, and how to measure whether it actually drove a customer to you.

Why Radius Size Matters More Than You Think

A geofence is a polygon around a physical location, and advertisers choose the radius, usually 100 meters to 1 mile. Most platforms default to 1,000 feet (about 300 meters). The smaller the radius, the more expensive the impression because fewer people see the ad. The larger the radius, the more money you waste reaching people too far away to visit you today.

For a dental office targeting a competitor's building, a 300-meter radius is tight enough that almost everyone in it is close to that office. For a home service business like plumbing or HVAC, a 1-mile radius might still be too small because customers are willing to travel 5 miles for an emergency service call.

• Competitor geofence: start at 300 meters unless the competitor is in a large office building, then go to 500 meters
• High-traffic location geofence (mall, business park): use 600 meters to 800 meters to catch people arriving and leaving
• Service area geofence (your own neighborhood or zip code): use 1 mile or larger, but be honest about your actual service radius first
• Event geofence (conference, trade show): use 300 meters; attendees are concentrated and high-intent.

Frequency Caps: Stop Showing the Same Ad to the Same Person

Geofence platforms track individuals (via device ID), not locations. That means if someone walks through your geofence every day, maybe they work there or live nearby, they'll see your ad every day unless you set a frequency cap. Show an ad more than three to five times per week to the same person, and you stop converting them and start annoying them.

The right frequency cap depends on your conversion timeline. A plumber responding to an emergency call needs to reach the customer fast, maybe two to three times per week for two weeks is enough. A dentist trying to get someone to schedule a cleaning in the next month might want a cap of five times per week for four weeks.

• Emergency services (plumbing, electrical, locksmith): 2–3 impressions per person per week, run for 2–3 weeks
• Appointment-based services (dental, medical, salon): 4–5 impressions per person per week, run for 3–4 weeks
• Retail or walk-in services: 3–4 impressions per person per week, run for 2–3 weeks
• High-consideration services (roofing, HVAC replacement): 5–6 impressions per person per week, run for 6–8 weeks

Frequency caps are not about being nice to the customer. They're about protecting your budget. Every impression beyond the conversion threshold is wasted money.

Attribution: Did the Geofence Actually Drive the Lead?

This is where most geofence campaigns fail. A customer sees your ad while driving past your competitor's office. They get home and Google your business. They fill out a form on your website two hours later. Did the geofence drive the conversion, or did the organic Google result? Your analytics will credit Google. You'll never know the geofence worked.

The only reliable way to measure geofence attribution is to ask the customer. Your booking form, phone script, or intake process needs a field: 'How did you hear about us?' And when someone says they saw an ad, you need to follow up: 'Where were you when you saw it?' Most won't remember. Some will say they were near a competitor's location, which is your signal.

A second method is to use a dedicated phone number for the geofence campaign. If you have different phone numbers for different channels, calls to the geofence number prove attribution. This only works if the number is visible in the ad and the customer actually calls from inside the geofence.

• Add a form field: 'How did you hear about us?' with options including 'Saw an ad'
• If they select 'Saw an ad,' ask: 'Do you remember where you were when you saw it?'
• Use a unique phone number in the geofence ad and track calls to that number separately
• Match the time of the conversion to the time the person was inside the geofence by checking device data your platform provides

Set Up Attribution Windows Correctly

An attribution window is the timeframe between when someone sees an ad and when they convert. A customer sees a geofence ad on Monday and books an appointment on Thursday, which is a three-day window. If your window is set to 24 hours, you won't credit the geofence. If it's set to 30 days, you might credit geofence for a customer who saw the ad once and converted weeks later through organic search.

For local services, the right attribution window depends on how fast customers decide. Emergency services need a short window: 24 to 48 hours. Planned services need longer: 7 to 14 days.

• Emergency services: 24–48 hour window
• Appointment services: 7–14 day window
• High-consideration services: 14–30 day window
• Never use a window longer than 30 days for geofence, because too much credit goes to other channels.

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