Eligibility Sequence is the order in which visitors are considered for assignment to your active Campaigns. When assigning a visitor to a Campaign, SiteSpect attempts to assign the visitor to the Campaign they are eligible for with the lowest Eligibility Sequence. Eligibility Sequence numbers range from one through nine, for all Campaign types except for Origin Experiments.
For example, a visitor is evaluated first for Eligibility Sequence 1 Campaigns. If the visitor is not eligible for any Eligibility Sequence 1 Campaign, then they are evaluated for Eligibility Sequence 2 Campaigns, and so on. By default, Campaigns (except for Origin Experiments Campaigns) are set to 5. If you want a particular Campaign to have more assignments, set it to 4.
In general, Campaigns with Audiences should have a lower Eligibility Sequence than those without Audiences. This allows SiteSpect to first evaluate visitors for Campaigns that have Audiences. Visitors who are not eligible then spill over to higher priority Campaigns that may be all-inclusive (i.e., have no Audiences).
Eligibility Sequence works the same way for Origin Experiments Campaigns, except that the range of Eligibility Sequences is from negative nine to negative one (-9 to -1). Campaigns that have a -9 Eligibility Sequence are assigned visitors first; Campaigns that have a -1 Eligibility Sequence are assigned visitors last.
Some useful Visualizations on this topic can be found below: