Quick Answer
Store the source on every opportunity at the moment it is created, track it through closed, completed and collected stages, then compare spend to collected revenue by source. Attribution fails when source data is added later or when revenue is reported inconsistently.
Capture the source at creation
Campaign, ad, keyword, landing page and channel should be attached to the opportunity record automatically. Reconstructing it afterward from memory or spreadsheets never holds up.
Follow it to collected revenue
Closed is not collected. Attribution that stops at the sale overstates performance, because cancellations and shrinkage are real.
Handle calls as first-class conversions
In most service categories the majority of revenue starts with a phone call. Tracked numbers per campaign are not optional.
Accept some ambiguity, then be consistent
Some customers see an ad, ask a neighbor and then search your brand. Perfect attribution does not exist. A consistent, documented rule beats a perfect model nobody applies.
How Furlan Systems applies this
We fund and operate this work directly: capital, advertising, technology, follow-up, sales and closing. Operating partners provide capacity, operations, fulfillment and customer experience.