This article lays out an effective strategy to engage passive candidates: using retargeting to keep their job opportunities in front of them over time. It discusses why some passive candidates are hesitant to apply for a position right away, and discusses how social media platforms can be used to target people who may be interested in the role but aren't actively applying. The article also provides tips for crafting marketing campaigns that will reach passive candidates and strategies for customizing messages for each target audience. Finally, it presents ways to measure and optimize retargeting efforts.