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.
Click here to read our creative and technical requirements for your ads. Ads must adhere to all advertising guidelines.
To check the audit status of your ads, go to Manage-> Ads and look at the information in the table there.
If an ad fails creative audit, you will get 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 under Manage-> Ads to make the changes suggested in the ad status e-mail you received, and save the ad again. It will be resubmitted for audit.