Tracking of non-users

Q: How does Facebook use social plug-ins to track non-users?

A: Facebook sets a tracking cookie ( datr ) when a non-user...

visits a Facebook page (e.g. event page, fan page etc.)

visits certain third-party websites including myspace.com, mtv.com, okcupid.com

opts-out from interest-based advertising on the European Digital Advertising Alliance website (specifically recommended by Facebook to European users)

Once the cookie is set, all the later visits to sites that include Facebook social plug-ins can be tracked and linked by Facebook using that cookie.

Q: Can Facebook track me even if I don't click the social plug-ins?

A: Yes. Visiting a page with social plug-ins is enough for being tracked once you have the cookie (see above).

Q: Does Facebook only set cookies on Facebook pages (when it's a first-party)?

A: No. For example, Facebook sets a tracking cookie ( datr ) on certain sites that use Facebook Connect (e.g. myspace.com, mtv.com, okcupid.com). Facebook also sets the same tracking cookie on the European Digital Advertising Alliance website if you try to opt-out.

Q: Do Facebook social plug-ins set cookies?

A: Mostly no. But on a small number of sites, Facebook social plug-ins do initiate a request to a URL starting with pixel.facebook.com/si/kappa/ which then sets a tracking cookie ( datr ).

Q: In the report you say Facebook sets a tracking cookie on the European opt-out site, but not on the US & Canadian site. Why the difference?

A: We have no idea.