Anyone can search the Ad Library by advertiser or keyword to see active ads, when they started running, and which platforms they appear on. Ads about social issues, elections, or politics are kept for seven years and include extra details such as spending ranges, impressions, the 'Paid for by' disclaimer, and audience demographics.
Beyond transparency, the Ad Library is a valuable competitive research tool: it shows which offers, formats, and messages competitors are investing in, and long-running ads hint at what's working for them.
Example
Before launching a campaign, a dental practice searches the Ad Library for local competitors and sees that most are promoting free whitening with a new-patient exam.
How Sloss Digital uses it
We use the Ad Library for competitive research on every new account and to monitor political ad activity for our campaign clients.