gclidgclid

With auto-tagging on, Google adds a parameter called gclid to the landing page's address when an ad is clicked: yourbrand.example/?gclid=…. It identifies that click, so Google Ads and Google Analytics can tie a later conversion back to the campaign, ad group and keyword. Redirects and click trackers along the way have to pass it on.

Some iOS traffic carries gbraid or wbraid instead. Google's API documentation describes gbraid as present when someone clicks an ad on the web and goes to an iOS app, and wbraid when someone clicks an ad in an iOS app and goes to a web page.

• A gclid on a landing address means the visit came from a Google ad, though not necessarily one of yours.
• Beside it, parameters your team didn't set point to someone else's tracking on the ad.
• Safari removes some tracking parameters from links opened in Private Browsing and from links shared in Mail and Messages.

How a sale gets credited shows where the identifier fits.