Geofencing lets you show ads to people who walked into a specific place. It sounds like magic and gets sold like it. Here's how it actually works, what it costs, where it fits, and when to say no.
Somebody has pitched you geofencing. Draw a boundary around your competitor's parking lot, the pitch goes, and everyone who walks in sees your ad for the next thirty days. Draw one around the convention center and capture every attendee. It sounds like a superpower, and the salesperson has a slide deck to prove it.
Geofencing is a real tool with a narrow set of jobs it does well. Most of the businesses I've seen buy it didn't have one of those jobs. Here's what it is, what it costs, and how to tell whether you're the exception.
What Geofencing Actually Is
A geofence is a virtual boundary drawn on a map, usually a few hundred feet across. Advertising platforms that use location data from mobile apps can note which devices were inside that boundary and then show ads to those devices later, as they browse other apps and websites. Most geofencing runs through programmatic display: banner and video ads on the open web and in apps, not on Google search and not, in most cases, on Facebook or Instagram.
Three variations you'll hear about:
- Geofencing: Target devices seen inside a boundary (a competitor, a venue, a job site, a neighborhood).
- Geoconquesting: The competitor version specifically. Show ads to people who visited a rival's location.
- Geotargeting: Just showing ads in a city or radius. Every ad platform does this. It isn't geofencing, though it's often sold under the same name.
Two things the pitch tends to skip: the ads show up later and elsewhere, not the moment someone walks in, and you're buying display ads, which most people scroll past without registering.
What It Costs
Geofencing is sold by vendors and agencies on a cost-per-thousand-impressions basis, and almost always with a monthly minimum. Expect a few hundred to a few thousand dollars a month depending on the vendor and how many fences you run, plus setup and creative. Because the audience inside a fence is small, budgets often go unspent or get quietly widened to a whole zip code to fill the order, at which point you've bought ordinary display ads with a fancier name.
Ask any vendor three questions before signing: how many unique devices do you expect to capture per month per fence, what share of my budget will run against those devices versus a broader area, and what exactly will I see in reporting? If the answers are vague, so is the product.
Where It Works
Geofencing earns its keep when the place someone visits says something specific about what they need, and the purchase is large enough to justify a small, expensive audience.
- Events and trade shows. A B2B service business fencing the convention center during an industry conference reaches a concentrated, relevant audience for a few days. This is the strongest use case.
- High-value conquesting. A car dealership fencing a rival dealership, an orthodontist fencing a competitor's office. Big ticket, clear intent, worth the premium.
- Job sites and new developments. A roofer or landscaper fencing a new subdivision under construction, reaching new homeowners as they move in.
- Recruiting. Fencing a competitor's facility to reach their employees with a hiring message. Unglamorous and effective.
Where It Doesn't
- Routine local services. A dog groomer fencing the dog park, a restaurant fencing a rival restaurant. The audience is tiny, the ad is ignored, and the dollars would do far more on Google or as a local Meta campaign.
- Anything urgent. Nobody with a burst pipe is waiting to see a banner ad. Search wins that customer.
- As a first paid channel. If your Google Business Profile isn't finished and you're not running search ads, geofencing is a decoration on a house without a foundation.
The Limits Worth Knowing
The location data behind geofencing comes from apps that ask for permission to track. Since Apple introduced App Tracking Transparency in 2021, most iPhone users decline, which shrinks the pool of devices any vendor can see. Android has tightened as well. The practical result: the audience inside any fence is a fraction of the people who were physically there, and it skews toward whoever said yes to tracking.
Attribution is the other weak spot. Vendors report "conversion zone" visits, meaning a device that saw the ad later showed up at your location. It's suggestive, not proof. Someone who was already coming counts the same as someone the ad persuaded. Treat those reports as directional at best.
"The question isn't whether geofencing works. It's whether the place you're fencing predicts a purchase big enough to pay for the privilege."
How to Test It Without Getting Burned
If you have one of the strong use cases above, run a small, time-boxed test:
- One fence, one event or one competitor, 30 to 60 days.
- A landing page or phone number used only for this campaign, so you can see what it produced without relying on the vendor's dashboard.
- Creative that acknowledges where they were, tastefully. "Saw us at the show?" outperforms a generic banner.
- A written definition of success before you start. "Twelve qualified conversations from the conference" beats "brand awareness."
- Compare the cost per real conversation to what the same money buys on search and Meta.
If it wins, keep it for that use case. If it doesn't, you've spent a modest amount to learn something real, which is more than most geofencing buyers can say.
The Bottom Line
Geofencing is a scalpel being sold as a hammer. For event marketing, big-ticket conquesting and a few specialized situations, it's worth a test. For everyday local marketing, the same dollars go further on the channels covered in the local marketing guide: a finished Google Business Profile, search ads for high-intent services, and Meta for staying in front of people who already found you.
Strategy decides which. The pitch deck shouldn't.