A segment execution is either persisted or in-flight.

When an inference happens in real-time, our services identify when a user belongs to a particular segment. A user will not stay in this segment for the duration of their on-site journey, but rather matches different segments at different times.

Persisted segment executions

A persisted segment execution is initialised by a segment that matched at some point during the user's session. Even though a user may no longer match this segment, persisted segment executions continue to be initialised.

One reason you may want to use persisted segments is when we don't want to confuse the end user by showing and then removing elements surfaced on the page, e.g. if we surface a discount code, users will expect that to be retained throughout their journey.

In-flight segment executions

In-flight segment executions are initialised by point-in-time segment matching - they don't care about whether a user matched a segment earlier in their session, but rather, continually re-assess "is a user matching the segment right now?"

In-flight segment executions will be initialised more sporadically, since a user may match a segment, then not match a segment, then match again, and so on -

Combined with segment execution triggers, this type of matching can be effective when you want to tailor content to the right here and now - i.e. where appropriate content can change in relation to phases of intent.