By default, the Broadstreet ad server de-duplicates campaigns on a given page load so that the maximum number of advertisers are represented. The setting that controls this behavior is on the Edit Campaign page. It is called Display Type.
There are currently three types of Display Types:
The default behavior described above. 1 ad from a campaign at most on a given time.
An alternate behavior where a campaign can be repeated, but not the same ad from the same campaign.
An alternate behavior where a campaign must be repeated, but not the same ad from the same campaign. This is intended for roadblock-style campaigns where advertisers demand that their campaign ads are always displayed together. For example, this could be used to make sure that a leaderboard is always coordinated with a sidebar unit.
This style of campaign requires that the first unit on the page, usually the leaderboard, is used in the campaign. If the leaderboard or first unit selects and loads a campaign that has forced repeating, any subsequent units with placements from that same campaign will be forced to match that campaign.