While most of the time, Supermetrics Data Grabber matches exactly the figures that the Google Analytics web interface displays, sometimes there are discrepancies. There are two common reasons for these discrepancies:
- Google samples the results it delivers to Supermetrics Data Grabber. In some cases, Google uses sampling to calculate the results of queries, which can cause differences between Supermetrics Data Grabber and Analytics. The magnitude of the discrepancies is usually in the range of 1-4 %. Supermetrics Data Grabber displays a note in the reports where it sees that Google has used sampling. Sampling occurs most often in queries that include an advanced segment, or where the data is split by multiple dimensions. Supermetrics Data Grabber versions 1.68 and newer have a setting that can be used to reduce the likelihood of sampling occurring.
- The Google Analytics API and the Google Analytics web interface are not always totally in sync. Supermetrics Data Grabber relies on the Google Analytics API, which may in some cases deliver figures which differ from the Analytics web interface. Small differences can be seen every now and then, but sometimes bugs in Google's end cause major discrepancies. From our experience, bugs like this happen a few times a year. If you suspect something like this may be affecting your reports, there are a few places where you can investigate the issue:
- Analytics API discussion group. When people notice bugs, they are usually posted here:
- Analytics status dashboard. Here you can see the status of the Analytics API and other Analytics services, bugs may be shown here.
- Analytics API notify list. Serious issues may be posted here by Google.
- Analytics query explorer. This is Google's own API tool, which you can use to confirm the results showed by Supermetrics Data Grabber. If this tool agrees with Supermetrics Data Grabber and differs from the Analytics web interface, then it indicates a bug in Google's end. On the other hand, if Google's API tool and the Google Analytics web interface match, and Supermetrics Data Grabber shows something different, that indicates a problem in our end; in this case, please contact us immediately.
When you see a discrepancy, before notifying us of the issue, please follow these steps:
- Check if the report includes a note such as this: "This report contains sampled data (sampling done by Google)". If this is the case, and the discrepancy is just a few percent, then it's very likely caused by the data sampling. In Supermetrics Data Grabber v. 1.68 and newer, you can use a setting on the Analytics sheet to avoid sampling in most cases.
- Try to fetch the same data with Google's own API tool. If the results match Supermetrics Data Grabber's, then the issue is in Google's end and we can't fix it.
- Download the latest Supermetrics Data Grabber version. If the discrepancy is caused by a bug in Supermetrics Data Grabber, it may have been fixed already in the latest version.