Evidence in out of home advertising reviews

What to take away

An out of home advertising agency review is a documented assessment of how a supplier sells, plans and reports OOH space, based on published evidence rather than a test campaign.

What a review actually assesses

A review sets out its scope first.

For OOH, that usually means the supplier's inventory list, the formats offered, the booking process and the audience data behind each location.

The reviews and comparison methods guide shows how a single review sits alongside cost checks and contract terms in a full buying decision.

Ask which documents the reviewer obtained and which were refused. A review that lists its sources can be checked; one that does not is a reading exercise.

A rate card or a sample post-campaign report is evidence; a sales presentation is a claim until its numbers can be traced.

A desk review cannot confirm screen uptime or lease renewal.

Where agency claims end and evidence starts

Route is the UK's out-of-home audience measurement service. Suppliers may publish reach or impression figures, but a review should identify their measurement source.

Treat supplier figures as claims unless the review names the measurement source and date. For audience figures, ask whether they are measured by Route and what locations, formats and period they cover.

For OOH audience claims, use Route's audience measurement rather than general population statistics from the Office for National Statistics. A review should identify the locations, formats and period covered by the figures.

For non-broadcast OOH advertising, check the CAP Code and relevant Advertising Standards Authority rulings. A review should identify the rule relevant to the claim or format.

Outsmart is the UK OOH industry body, and its Code of Conduct sets standards for members. Membership or code compliance is not, by itself, evidence that a campaign delivered.

Awards and trade body memberships are not delivery evidence.

For example, a review covering Greater Manchester might assess digital six-sheets at transport interchanges. A rate-card entry should name the format, site, period and actual quoted cost. An illustrative template might read: digital six-sheet, Manchester Piccadilly, two weeks, cost: quote from dated rate card, 120,000 weekly impacts: claim requiring a source and date. This is a template, not a real rate-card entry or verified audience figure.

How to score a review before you trust it

Score the review, not just the supplier.

A usable review states its method, dates its evidence, and separates what was assessed from what was not.

If it claims hands-on testing the reviewer could not have done, discount it.

Treat a score as provisional unless the evidence behind it is dated and identifiable. For example, a cost score of 8/10 without a dated rate card stays provisional.

Check the cost versus coverage weighting. Hidden weights reflect the reviewer's priorities.

Keep the evidence score separate from the fit score. A well-documented supplier can still be wrong for your region.

Treat a supplier ranking without that detail as unverified.

Decision table

Common questions

Can an agency review tell me which supplier will perform best?

No. A review compares published rates, formats, data sources and contract terms. Performance depends on your creative, locations and measurement.

Do reviews cover suppliers outside England?

Some do, but rules and data differ by nation. Name Scotland, Wales or Northern Ireland when a requirement differs from England.

How often should a review be refreshed?

Whenever the evidence changes, such as a new rate card or inventory list. A review over a year old is a starting point.

What should I ask a supplier after reading a review?

Ask for the current rate card, a sample post-campaign report and a data collection statement. If a supplier will not share them, record that.