Were all your ads approved?
If your ads don't pass audit, they won't serve impressions. If every ad included in a campaign fails audit, no impressions will be served.
To check the audit status of your ads, go to the "Manage" -> "Ads" section of your dashboard and look at the information in the table there.If an ad fails creative audit, you will find out in an e-mail sent to the address associated with your account. To make changes to an ad and resubmit it for audit, click the "edit" link next to it in the "Manage" -> "Ads" section, make the changes suggested in the ad status e-mail you received, and save the ad again. It will be re-submitted for audit.
Take a look at some other ways to increase reach:Is your audience large enough?
Is your campaign active and ready to serve?
Are you using too many ads?
(Web Only) Are you including at least one of every banner size?