The Frequency Capping section in the assignment page allows you to set a limit on the number of times an ad will be served. In AdButler, you can set a limit per user, per day, or both.
Per user limit
This uses a cookie to determine how often a single user can view the assigned ad or ads within a set amount of days.
This limits the views or clicks that the assignment can receive per day.
If you set frequency caps in a campaign, those limits will be shared by ALL of the ads in the campaign. Depending on the number of ads in the campaign, this could significantly reduce the number of times that each ad will be served.