# How we write, source and verify

Signage ROI publishes guides that can be checked line by line. This page states the rules behind them.

*Verified 2026-10-25 · https://roitechnologies.net/methodology/*

> **Short answer:** Signage ROI takes each fact from a named public source, shows the date the source was read, and re-verifies the facts on a schedule. A fact that no public page states is shown as not published, never estimated.

## What counts as a source

- **Primary:** the vendor's own pages, product documentation and announcements, and manufacturer or standards documentation.
- **Secondary, labelled as such:** trade press with a named publication and date.
- **Not used:** anonymous forum posts as proof, unsourced statistics, and prices quoted in sales calls.

## How rankings are built

A ranking names its criteria before it lists a single product. A product earns a criterion only when its own published pages state it, and the table shows which criteria each product meets. Rankings answer a narrow question, for example which platform suits small teams with mixed screens, and do not claim a single best product for every buyer.

## Verification schedule

- Facts and supported devices: re-verified every quarter and after any announced product change.
- Every page shows its last verification date, and the [changelog](https://roitechnologies.net/changelog/) lists what changed.

## Corrections

A reader who finds a factual error can send the correct public source to [contact@roitechnologies.net](mailto:contact@roitechnologies.net) and the page is updated with a changelog entry.

## Coverage

Signage ROI covers digital signage and narrowcasting, including Screenbird. Every product on a ranking is checked against the same published criteria, and the criteria are listed on each ranking page.