What are mega users?
When the same user ID (uid) is set for more than one individual with the Identify Users API, Fullstory will coalesce these individuals and their sessions into the same user. While this is beneficial for tracking a single person across different devices, it can lead to data inconsistencies when multiple different individuals share the same uid. In cases where there are a large number of different individuals who have the same uid set, it can lead to the creation of what we call a mega user.
How mega users affect your analytics
Mega users can significantly impact the accuracy of your analytics data in several ways:
- Funnel Analysis: A mega user might appear to complete a conversion path multiple times, inflating your conversion rates and masking actual user behavior patterns.
-
Segment Data: User segments may become skewed when mega users are included, as one
uidcould represent hundreds of different actual users with varying characteristics. - Engagement Metrics: Metrics like average session duration, pages per session, and return visit rates can become artificially inflated due to multiple users being counted as one.
- User Journey Analysis: When different users are merged into one mega user, it becomes challenging to track genuine individual user journeys and behavior patterns.
How are they created?
Mega users occur when an exceptionally high number of sessions are linked to a single uid, often resulting from how the Identify Users API is implemented or from usage of automated testing or bots.
Note: We officially released V2 of our Identify Users Browser API (e.g.
setIdentity)
on
November 1st, 2023. If you're still using V1 of our Browser API (e.g.
FS.identify),
please refer
to
our V1 API documentation found
here.
If you were using Fullstory prior to August 3rd, 2023 and aren't sure which version of our Browser API is compatible with the data capture snippet deployed on your website, please refer to these instructions to confirm.
Mega users are flagged in Fullstory when these specific thresholds are met:
- More than 250 unique cookies are associated with a single
uidin a day - Exceeding a consistent limit of 45 unique cookies for one
uid
When either of these thresholds are reached, new sessions where a user is identified with that uid will begin creating separate user cards rather than being consolidated into one.
Here is what this could look like when searching by the uid of a mega user. Note that when searching for a single uid value, multiple users are still returned in the session playlist:
What causes mega users?
There are a handful of common scenarios that can lead to the creation of mega users:
- Implementation patterns in
FS.identify(v1) orsetIdentity(v2) that go against best practices (i.e. don’t maintain uniqueuidvalues) - Automated testing or bot activity
- Shared login credentials used by multiple individuals
Managing mega users
To maintain accurate analytics data, you may want to review your Identify Users API implementation to ensure each individual user receives a unique uid. This is in keeping with Fullstory’s best practices, and preventing the formation of new mega users helps to keep your analytics data clean and reliable.
Once the cause of a mega user has been identified and addressed, you will want to reach out to our Support team for assistance with deleting the mega user data that is affecting the integrity and accuracy of your analytics. It’s important to note that the previously-captured mega user data will continue to affect analytics until a deletion of the mega user and all sessions captured under that coalesced user.