When someone converts on your site, the details they submit are securely hashed (one-way encrypted) and sent to Google, which matches them to signed-in Google accounts. That lets Google attribute conversions that would otherwise be lost to cookie restrictions, cross-device journeys, and browser privacy features. Enhanced conversions for leads extends this to offline outcomes, matching later sales back to the original lead.
Better measurement leads to better bidding: Smart Bidding can only optimize toward conversions it can see. Enhanced conversions can be implemented through the Google tag, Google Tag Manager, or the API, and should be set up in a way that respects user consent.
Example
A contact-form submission sends a hashed email address along with the conversion, so Google can credit the ad click even though the user clicked on their phone and converted later on a laptop.
How Sloss Digital uses it
We implement enhanced conversions for web and for leads on lead-gen accounts, which typically recovers conversions that were going unmeasured and gives Smart Bidding more to learn from.