When creating a segment, you can use a CSV for either the Visitor ID or Account ID field. This article explains why the Eligible Visitors number for a segment created in Pendo using a CSV might be different from expected.
Environment: People > Segments
Issue
When you use a CSV for Visitor ID, the number of Eligible Visitors can differ depending on where you're looking in Pendo: segments, guides, and reports. This discrepancy could be due to some or all of the Visitor IDs in the CSV not existing in Pendo yet. This is expected behavior. For more information, see the Segments article.
Explanation
When you apply the segment to other views in Pendo, the Eligible Visitors number is calculated differently.
Pendo automatically creates a visitor record when an event is first received for a visitor. If a visitor has never had an event sent to Pendo, they have no visitor record in Pendo. When viewing Eligible Visitors from the People > Segments page, the number of Eligible Visitors includes every visitor in the CSV file, even if they've never sent an event to Pendo.
When the segment is applied to a guide or a report, the Eligible Visitors number includes only Visitor IDs that exist in Pendo. These are visitors that have had events sent to Pendo. For reports, these visitors must also have events associated with them that fall within the report date range.
Example
A segment called "Marketing List" with ten Visitor IDs is created using a CSV. From the Segments page, you can see ten Eligible Visitors. This doesn’t mean that all ten visitors exist in Pendo. It only means that the CSV file has ten entries for Visitor ID.
If only three visitors in the segment have had events sent to Pendo, there will be only three Eligible Visitors that exist in Pendo.
Thus, when the same segment is applied to a guide in Pendo, there are only three Eligible Visitors for that guide. Similarly, when the same segment is applied to a report, such as the Visitor's List, with a date range of "Today", there are only three Eligible Visitors – the number that had events sent to Pendo within the date range.
Solution
The difference in the number of Eligible Visitors is typically due to the Visitor IDs in your CSV not existing in Pendo until all visitors have had an event sent to Pendo.
If you plan to create a segment using a CSV for guide targeting, you don’t need to do anything for the Visitor IDs that don’t exist in Pendo yet. Visitor activity is collected when the user accesses your application, and the visitor record is automatically created in Pendo. Pendo detects that the visitor is eligible for a guide based on the segment, and if all other guide display requirements are met, that visitor then sees the guide.
This is also true for segments using a CSV for Account IDs.