Offline conversion import is the process of sending a conversion that happened away from a website, such as a signed contract or a deal a CRM marks won, back into an ad platform after the fact. The platform matches it to the original ad click using an identifier stored at that click, most often a Google Click ID (GCLID), rather than anything read from the website itself. Once matched, the offline outcome counts toward the campaign's reported conversions and, where enabled, toward what the bidding algorithm optimizes against.
Why it matters for agencies
For an agency, offline conversion import is the difference between a campaign that optimizes on a form fill and one that optimizes on the deal the client's sales team actually closed. Plenty of accounts stop measuring at the form or the phone call, so the bidding algorithm never learns which of those leads became revenue and which went nowhere, and keeps buying more of whatever produces cheap leads rather than paying customers. A client asking why cost per lead looks great while sales is unhappy is often looking at a CRM outcome that never reached the platform at all.
What teams get wrong
The most common failure is assuming the import will work without anything stored at the moment of the original click. Google's own setup guidance is explicit that the GCLID, the identifier Google Ads attaches to a link when someone clicks an ad, has to be captured and stored with whatever lead information the site collects, because that identifier is what the later offline conversion gets matched against. A CRM that only saves a name and a deal stage has nothing to send back weeks later, so the import returns zero matches and looks like a CRM problem when the real gap sits on the website form that never stored the click identifier.
The second is confusing this with enhanced conversions, a different mechanism doing a different job. Google describes enhanced conversions as a feature that supplements an existing conversion by sending hashed customer data alongside it, while an offline conversion import brings in a new conversion event for an outcome the website never recorded at all, such as a deal closed weeks after the form fill. Archon Labs sees the two treated as interchangeable, so a team assumes enhanced conversions solved the CRM-revenue gap when the feature cannot see anything that happens after the form fill.
