If your campaign is set to inactive, or you gave it an end date that has come and gone, it won't serve any impressions.
To check the start and end dates of your campaigns, go to Manage-> Campaigns and look at the information in your campaign table.
If your campaign is set to inactive, or you gave it an end date that has come and gone, it won't serve any impressions.
To check the start and end dates of your campaigns, go to Manage-> Campaigns and look at the information in your campaign table.