There could be a number of reasons why your campaign may not be getting traffic:



Account Balance (Is your campaign below our threshold of $25.00?).

Campaign Budget Reached.
Blocked Ad Attribute or Vertical.
No Creatives Online For Specific Ad Size.
Retargeting Audience Too Small.
Limited of Impressions Available for Geo Location.
Limited of Impressions Available for Banner Sizes.
Campaign is Running Outside date range selected.