When a user visits your Site, SiteSpect determines which Campaigns that user is assigned to depending on Campaign Set, Campaign Overlay settings, Audience, Eligibility Sequence, and Traffic Split/Frequency.
SiteSpect may assign one user to multiple Campaigns at the same time, but to only a single Variation Group in each Campaign and never the same Campaign again.
For MVT Campaigns, you can configure the length of time a user is assigned to a Campaign using the Time & Duration settings of the Campaign.
Users who are not counted when assigned to a Campaign are then unassigned and are eligible for to be reassigned to the Campaign on their next visit as long as they still meet the conditions.
An assigned visit is a visit during which the user is assigned to at least one Campaign. Sites with several active Campaigns typically have a low number of unassigned visits.
In addition, if a user fails to be included in the Audience for a Campaign during one visit, the same user may be assigned to the same Campaign if the user later meets the Audience requirements.