The right data has to land in the right property.
We extract every GA4 measurement ID found on the page (format G-XXXXXXXXXX), validate that each one has a matching gtag('config', ...) call, and compare what we find against the measurement IDs you told us to expect.
A measurement ID tells GA4 which property to send data to. If the wrong ID is on the page, your data is going somewhere else — often a test property, an old account, or a competitor's setup left over from a prior agency. If the ID is present but no config call runs, gtag.js loads but never initializes — so data is captured but never sent.
An agency runs ads for 30 clients. Two clients' sites are accidentally configured with each other's measurement IDs after a copy-paste mistake. For months, conversion reports for both clients are inflated, and ad spend decisions are based on data from the wrong site.
A Fortune 500 redesign launches with the dev team's test measurement ID still hard-coded into the production header. All real visitor data goes to a sandbox property nobody monitors. They lose 4 weeks of data before someone notices their main property is flat.
A dentist office hires a new web developer who installs GA4 without removing the old Universal Analytics tag. Both fire, but UA stopped collecting data in 2023 — the office runs reports off it for a year before realizing nothing has been recorded.