Facebook recently announced that they will begin offering a first-party cookie option for the Facebook Pixel. Previously, they only used third-party cookies. From their documentation:
You can now use both first and third-party cookies with your Facebook pixel. The difference between first and third-party cookies lies in who owns the cookie.
First-party cookies are owned by the website a person is currently viewing, while third-party cookies belong to a website other than the one a person is currently viewing. Compared to third-party cookies, first-party cookies are more widely accepted by browsers and stored for longer periods of time.
The option to use both first-party and third-party cookies will be released on October 24, 2018.
My questions are:
- How does this work technically?
- How can a third-party JavaScript script set a first-party cookie?
- What was preventing Facebook from doing this before?
- What are the implications for the user's privacy?
- Does this successfully get around Safari's new intelligent tracking protections?
I'm searching for the technical details that haven't been included in Facebook's announcement.