Can we adjust the dates for the segment population trend chart?
You cannot adjust the time frame. The set lookback is a maximum of 12 weeks. Keep in mind, if the segment was created less than 12 weeks ago you will see the segment creation date as the first date on the population trend chart.
How long does it take for a segment’s population to display in the population trend chart?
The trend chart is updated as soon as the segment is processed.
Why do I see "devices removed" a few days after the segment has been created even though I used a 30 / 90 / 180 day rule?
The reason your segments are showing "removed devices" already a few days after they have been created is our cross device functionality.
Each user creates multiple Krux User IDs (KUIDs). This is cookies in browsers as well as IDFAs or AdIDs for mobile apps. Once we can identify with our cross devices algorithm that two of these KUIDs belong to the same person, we increase the count of "people" by one and select one of the KUIDs to be the "leading" KUID, we call this one the "Uber ID".
There's some rules in place to determine which of the KUIDs is elected the Uber ID. This evaluation can change from day to day. E.g. if the Uber ID KUID is not active for a couple of days, it looses it's status as Uber ID. In this special case, the Uber ID is removed from the segment population list and shown accordingly as "deleted". The user is still part of the segment, but another one of his KUIDs is considered the new Uber ID and that is counted as an addition to the device population of that segment.
It is mainly Safari users to contribute to these Uber ID changes, as on Safari each page impression creates a unique new KUID.
We understand this is not intuitive to understand, so we will discuss internally how to make this more transparent.