Why doesn’t my 3rd party click tracking match my Facebook data?

Third-party platforms can only track linear conversions, where a user has clicked on an ad and converts on the same device.
Third-party platforms cannot track nonlinear conversions and they can’t accurately track users across devices.
Facebook, on the other hand, tracks conversions across devices and can also track nonlinear conversions (i.e., when a user clicks an ad, browses but leaves your site, then returns and converts).
To track these conversions, we use a 28-day window for views and a 28-day window for click-through.
Additionally, Facebook conversion tracking also tracks how your customers move between devices before they convert, which is important because cross-device conversions from ads are common and underreported by 3rd party platforms.

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