Almost every out-of-home supplier will tell you a campaign was a success. Far fewer can tell you where your advertising actually was. Those are different claims, and the gap between them is where most OOH reporting lives.
“GPS-verified” is a phrase worth interrogating rather than accepting, including when we use it. This piece sets out what conventional OOH delivery reporting actually measures, what a location trail adds, and — the part most suppliers skip — where the measured data stops and the modelling starts.
How out-of-home delivery is usually estimated
Traditional OOH was built around fixed sites. A billboard does not move, so the industry developed audience measurement that works for things that stay still: count the traffic passing a location, apply visibility factors, and derive an audience for anyone who buys that site. It is a reasonable model for a static panel.
Moving media inherits that approach without inheriting its logic. When the advertising is on a vehicle, the thing being measured is no longer a place. The usual answer is to estimate: take an average number of hours a vehicle is assumed to work, apply an average audience per hour drawn from industry norms, multiply by the number of vehicles, and present the result.
Every input in that chain is an average. None of them describes your campaign. If one of your vehicles spent three weeks off the road, the estimate does not know. If the fleet worked the suburbs rather than the centre, the estimate does not know that either. The number arrives with the same confidence whether it happened or not.
What a location trail records that a model cannot
A GPS log answers a narrower question, but answers it with evidence: where was this specific vehicle, and when.
From that you get things an average cannot produce — which boroughs a wrap actually spent its hours in, how that split across dayparts, whether a vehicle was working at all on a given day, and how the campaign's real distribution compares with the plan it was sold against. Across our partner fleet that amounts to 135,000+ miles a week and 7M+ miles a year, every one of them logged.
The useful consequence is that the reporting can disagree with the plan. An estimate never contradicts the proposal that generated it, because it is derived from the same assumptions. A location trail is capable of telling you that a campaign under-delivered — which is precisely why it is worth having, and why it has to be the thing that settles a capped pay-for-delivery bill rather than a document produced afterwards to justify one.
Measured, modelled, and the line between them
This is the distinction we would most like you to take away, because it is the one that separates honest OOH reporting from confident OOH reporting.
Measured: where each vehicle was, and when. Location, hours, zone, borough, daypart. These are recorded, not inferred.
Modelled: audience figures. Impressions are derived from measured on-street hours multiplied by an assumed impressions-per-hour rate; reach is that impressions figure divided by an assumed frequency.
We label modelled figures as modelled every time they appear, next to the measured delivery they are built from. That is not modesty. Reach and impressions for moving media cannot be counted — nobody is counting individual human eyes on a passing taxi, and any supplier implying otherwise is describing a capability that does not exist.
What GPS changes is the foundation of the model. An estimate built on measured hours from your actual vehicles is a materially better estimate than one built on assumed hours from a notional fleet. It is still an estimate, and it should still be labelled as one.
So the honest version of the claim is narrow: we can prove where your advertising was. We can give you a reasoned estimate of how many people saw it. Anyone collapsing those two sentences into one is overselling.
Why a report that does not reconcile is not a report
A delivery report makes a set of claims that have to agree with each other. Share-of-time by borough has to total 100%. The boroughs listed in a zone have to add up to that zone's total. Per-vehicle hours have to sum to the campaign's hours. If those numbers do not reconcile, the report is not evidence — it is a layout.
This is easy to say and easy to skip, so we made it enforceable. The sample delivery report shown on our homepage is generated at build time, and the build fails if the figures do not add up. Among the conditions it refuses to publish through:
- zone percentages that do not total 100%, because “the sample report must reconcile”;
- borough percentages that do not total 100%;
- boroughs whose figures contradict the zone totals shown on the other tab — the two views have to agree;
- an area name that is not a real London borough, so the map cannot quietly shade something that does not exist.
That sample is illustrative rather than a real client campaign, and it is labelled as such on the page. The point is the standard: a report that cannot survive its own arithmetic should not reach a client, and the most reliable way to guarantee that is to make it impossible to ship.
What your report actually contains
During a campaign, the data is available live — through a web portal, or via API and webhooks if you would rather pull it into your own stack. It can be reconciled to Route where that forms part of your measurement setup.
Afterwards you get the finished view: where each vehicle ran, by zone, borough and daypart, with the modelled audience figures presented alongside and labelled. Vehicles appear as numbers, never registrations — reports are anonymised, and a plate never appears in one.
How to read a delivery report you have been handed
Four checks that work on any OOH report, from any supplier:
- Do the totals reconcile? Add up the percentages. If a breakdown does not reach 100%, ask what is missing before you read anything else.
- Which figures are measured and which are modelled? If the report does not distinguish them, treat all of it as modelled.
- Is this my campaign, or a category average? Ask whether the audience number would change if your vehicles had driven somewhere else. If it would not, it is describing the format, not your booking.
- Could this report have told me the campaign under-delivered? If there is no mechanism by which it could ever have said so, it is not verification.
Question four is the one that matters most. Reporting that can only confirm success is marketing collateral with a chart in it.
Seeing it for yourself
There is a sample delivery report on our homepage — the borough map, the zone breakdown and the per-vehicle table — so you can see the shape of the reporting before you commit to anything. If you want to talk through how it would apply to a specific campaign, the number is 020 4577 0102.
For what a campaign costs and how it is priced, see how much taxi advertising costs in London.