Definition
Geofence accuracy (billboard mobile retargeting) — Geofence accuracy in the context of billboard mobile retargeting is the distance between a phone's reported location and its actual physical position when an ad platform decides whether that phone passed by a billboard. Accuracy depends on smartphone GPS quality, urban-canyon multipath effects, the platform's reliance on Wi-Fi/cellular fallback, mobile-ad-ID match rates, and whether the billboard's exact latitude and longitude is even disclosed.
A billboard mobile retargeting campaign draws a virtual radius — typically 50 to 200 meters — around a billboard's location. Ad platforms watch the bid stream for mobile devices that send a location request from inside that radius during the campaign's flight. The matching device's mobile advertising ID (MAID) is logged. Days or weeks later, when that same device shows up on a different app or website, the advertiser serves a follow-up mobile ad that references the billboard message.
The pitch is straightforward: a billboard plus a mobile retarget produces sequential exposure that out-converts standalone mobile by a factor of 3.9x in industry-aggregate data.
The mechanics make a lot of assumptions about location precision. Each one chips away at the conversion-lift number.
Manufacturer accuracy claims and field accuracy are different numbers. The cleanest field measurement comes from a peer-reviewed PLOS One study on iPhone horizontal accuracy:
A-GPS combining satellite + cellular network
Wikipedia — Global Positioning SystemiPhone 6 horizontal accuracy in dense urban setting
Smartphone GPS accuracy in urban environment — PLOS OneBuildings, trees, multipath reflection
TrackHawk — How accurate is GPSFour loss vectors sit between the billboard and the mobile retarget. Each is real and citable. None are unique to any single vendor.
If you're an HVAC contractor running a billboard on I-95 paired with mobile retargeting, the platform may report that X thousand mobile devices passed your board. The honest read on that number is:
WilDi Maps replaces the impression-and-retarget model with Cost Per Verified Delivery (CPVD): $0.20 per delivery to a real driver phone moving through a corridor you've leased. Each delivery is GPS-verified at the device level, not inferred from a bid-stream proximity guess.
The architectural difference is who owns the location signal. In billboard mobile retargeting, the platform infers location from a third-party SDK's bid request and pays an exchange to bid against guessed proximity. In CPVD, the operator's own application reports the device's GPS position from the device, in real time, through infrastructure WilDi controls. There's no exchange, no match-rate fallout, no bid-stream latency, no Middleman Tax.
For the full breakdown on where ad budget gets siphoned in the standard model, see What is the Middleman Tax?
The product
WilDi Maps is not a single flat-rate product. You pick the tier that matches how local you need to be. All three are GPS-verified per claim — no auction, no exchange rake, no Middleman Tax.
1-mile road strip
Premium
Hyper-local, just-in-time
Lease a one-mile stretch. When a driver enters the strip, they get a just-in-time message — perfect for emergency services, on-route specials, and anything where being right there now beats brand awareness later.
Best for
1-square-mile area
Premium
Hyper-local, area-based
Lease a one-square-mile block — not tied to a single road. Catches the residential cluster, retail district, or industrial park where your work actually lives. Same just-in-time delivery as tunnels; different geometry.
Best for
City-wide rotation
$0.20
per claim, fixed
City-wide brand presence on rotation. Highest reach for the budget — best when familiarity beats precision. The $0.20 fixed rate is the only flat-rate tier WilDi sells.
Best for
What the driver gets when an ad is claimed
If the driver wants to act on the ad, the app navigates them straight to the advertiser's location.
Click-through to any URL — ordering page, brand site, blog post, lead form.
Open a specific page inside the WilDi app — promo details, daily specials, claim instructions.
See the full pricing breakdown on the pricing page.
Geofence accuracy is how close a mobile ad platform's reported device location is to the device's true physical position. Theoretical accuracy is ~4.9 meters with assistive services (Wi-Fi, cellular) and 3–5 meters with clean GPS lock; in the urban environments where billboards typically live, peer-reviewed measurements show 7–13 meters of horizontal error and real-world accuracy can degrade to 10–20 meters when buildings, trees, or multipath reflection interfere.
Combining the smartphone GPS error (7–20 meters in urban environments) with mobile-ad-ID match rates (typically 60–80%), bid-stream latency, and undisclosed billboard screen coordinates from many DOOH networks, the practical accuracy of billboard mobile retargeting is materially worse than the marketing claim. A 50-meter geofence radius around a billboard does not produce 50-meter precision in who actually saw the board — it captures everyone the platform's bid-stream guesses might have been near the board, which includes non-buyers, passengers, out-of-market drivers, and unmatchable devices.
Industry coverage from MarTech and Marketing Dive has noted that some DOOH networks deliberately obfuscate exact billboard coordinates so competing networks can't reverse-engineer their inventory or flight schedules. The trade-off is that mobile proximity targeting becomes a looser estimate — geofence radii get inflated to compensate, which dilutes accuracy.
Cost Per Verified Delivery (CPVD) is a pricing model where you pay $0.20 per delivery (background); tunnels and zones priced for hyper-local precision — each time your message is delivered to a real phone moving through a corridor you've leased. The delivery is GPS-verified at the device, not inferred from a third-party bid stream. No auction, no exchange rake, no mobile-ad-ID match-rate fallout, no Middleman Tax.
The 3.9x lift is industry-aggregate data and is real on average — sequential exposure does outperform standalone mobile. The honest caveat is that the lift is measured against a baseline that already absorbed the accuracy losses. You're paying for the imprecise version of the workflow; the lift is the imprecise version's lift. A precise alternative (GPS-verified at the device) is a different architecture, not a tuning of the same one.
Billboards work for brand awareness on a national CPG-style budget. For a local service business measuring customer acquisition cost, the math rarely pencils out: even with mobile retargeting layered on top, the share of any billboard's traffic that's actually a homeowner-with-a-failing-system in your service area is small, and accuracy degradation eats further into that share. Fixed-rate verified delivery to a chosen corridor outperforms billboards on CAC for almost every local service vertical we've modeled.
About this analysis
Written by Timm Ross, founder of WilDi Maps · Jacksonville-based · Veteran-owned. Sources are cited inline; we update the numbers when the underlying research updates.
More about WilDi MapsFixed $0.20 per GPS-verified delivery. No auction, no bid stream, no Middleman Tax.
