Online banner advertising began in the early 1990s as page owners sought additional revenue streams to support their content. Commercial online service Prodigy displayed banners at the bottom of the screen to promote Sears products. The first clickable web ad was sold by Global Network Navigator in 1993 to a Silicon Valley law firm.
In 2017, Facebook partnered with fact checkers from the Poynter Institute's International Fact-Checking Network to identify and mark false content, though most ads from political candidates are exempt from this program. As of 2018, Facebook had over 40 fact-checking partners across the world, including The Weekly Standard.