What retention tells you
Retention for QR campaigns measures whether scanners come back: scanning again, returning to the site, staying subscribed, or buying a second time. Acquisition gets attention, but retention is where repeat value is built.Retention without a defined window is just a vague feeling. Pick 7, 30, or 90 days and stick to it.
How to compute retention
Retention = scanners who return within a chosen window divided by scanners in the starting group, multiplied by 100.Illustrative example numbers, not real-world data: 90 of 300 first-time scanners return within 30 days, giving 90 / 300 x 100 = 30% retention. The other 210 did not return in that window, which is normal for one-off offers and a warning sign for loyalty offers.
How to collect the data
Define the return action and the window before you start, then track the same starting group over that window instead of mixing in new scanners.Keep the raw counts, not just the final percentage. Raw counts let you recompute the metric if you later fix the definition, and they make it possible to spot a denominator problem, such as a week where exposures were estimated instead of counted. Store the counts in one place with the date range, the placements included, and the name of the person who pulled them. That small discipline turns a spreadsheet into an audit trail.
Reading the result
Never judge retention as a single number. Break it down by offer type, first-scan week, and placement. A campaign that looks average overall may be strong in one segment and weak in another, and the fix is completely different in each case. Compare the same placement against its own past, and compare different placements only when their audiences and contexts are genuinely similar. A short trend over four or more comparable periods is worth far more than a single snapshot, because it separates a real shift from weekly noise.Also check the relationship between retention and the metrics around it. If scans rise while conversions fall, the new scanners may be less interested visitors, or the landing page may have changed. If cost rises while retention stays flat, you are paying more for the same outcome. Metrics make sense in groups, not in isolation, and the habit of reading two or three together prevents most misreadings.