In a new blog post Facebook explains how the ad review system works.
Facebook ad review system is designed to review all ads before they go live. This system relies primarily on automated technology to apply Advertising Policies to the millions of ads that run across apps.
While our review is largely automated, we rely on our teams to build and train these systems, and in some cases, to manually review ads.
While ad review is typically completed within 24 hours, it may take longer, and ads can be reviewed again, including after they’re live. Based on the results of the review, an ad is either rejected or allowed to run. If an ad is rejected, an advertiser can create a new ad — either with new ad creative or by revising the rejected ad — or request another review if they believe their ad was incorrectly rejected.
Unlike the initial ad review, Facebook relies more heavily on teams of human reviewers to process re-review requests from advertisers.
Facebook may also investigate advertiser behavior: the number of previous ad rejections and the severity of the type of violation, including attempts to get around the ad review process.
This is how Facebook ad review systems looks like:
Facebook users can also report ads by clicking the three dots in the upper right hand corner of the ad. People can also report ads directly from the Ad Library. These reports are an important signal to ad review systems, and may prompt a re-review of the ad.