How ad retargeting works?
- by Bojan Babic
Recently, I read that Facebook ads are moving towards retargeting and got interested deeper into subject. Essentially, retargeting is technique advertisers use that tracks purchase intent by putting cookies into your browser and when you visit another website within ad network you will see ad for item you "wanted to buy".
In order this to for, both publisher and advertiser need to work together. Publisher needs add couple of lines of javascript and publisher need to be able to read this info across sites. In most cases, javascript inserts iframe from adnetwork domain. Iframe script sets cookies for both host domain and remote adnetwork domain.
However, Same Origin policy do not let iframes read/set content from parent domain. Is there something I'm missing here? Can someone explain how this technique actually works?