The five layers
GA4 raw event data
We sync your raw GA4 event data straight into BigQuery. This bypasses the sampling, unnattributed & data processing issues you see within the GA user interface. GA4 tracks events (page views, clicks, add to carts, purchases etc), landing pages and UTM parameters across your site. When a customer purchases, we match their session history to the Shopify order.This captures paid search, Meta ads, email clicks, and any UTM-tagged traffic. We look at the users first ever event on the website (that is not Direct or Unknown) for the attribution source. We also don’t bound this by time, meaning if you have a long purchase cycle (60+ days) we cater for that unlike GA standard reporting.This first event (click) model using raw ga4 data typically accounts for 60 - 70% of your order attribution.
Discount codes
Discount codes are mapped to channels, campaigns and ad groups via your configuration sheet. When a customer searches for your brand after seeing an influencer post, or being referred by a friend. We use the discount code at checkout to correctly attributes the order, even though GA4 saw it as direct or brand traffic.This is particularly valuable for influencer, referral program, direct mail, offline (out of home, tv), partnership and affiliate channels where customers often navigate directly rather than clicking a tracked link.
Shopify customer journey
Shopify independently tracks the last non-direct touchpoint before purchase. This is used as a fallback when GA4 and discount codes both return Direct or Unknown.Shopify’s journey data captures social media referrals, search engine visits and other touchpoints that GA4 may have missed due to tracking blockers or cookie restrictions.
Post-purchase surveys
First-party data from “How did you hear about us?” surveys (such as Fairing, Kno or Triple Whale) provides a final fallback for orders still attributed to Unknown, Direct, or Paid Search Brand.Surveys capture channels with no digital footprint: word of mouth, podcast mentions, TV ads, in-store recommendations, and other offline touchpoints that no click-based system can detect.
First-click vs last-click
Crux captures both first-click and last-click attribution for every order, giving you two complementary views of your marketing performance. First-click shows which channel introduced the customer to your brand. Last-click shows which channel drove the purchase. Both are valuable, but they answer different questions. First-click is the default across all Crux dashboards because it best measures acquisition activity, complemented by discount codes and post-purchase surveys. Last-click is surfaced for visibility and used primarily in CRM reporting (email and SMS channels), since those are low-funnel touchpoints that close sales rather than introduce customers. Example: A customer discovers your brand through a Meta ad (first-click), then returns two weeks later via a Google brand search and purchases (last-click). Both touchpoints are captured. The Meta ad gets credit in the first click model, while the Google search gets credit for the conversion in the last click model.In your Orders report, fields prefixed with “Last Click” show last-click data. Fields like Source, Medium, and Channel show the primary first-click attribution.
What happens to unattributed orders
After all five layers have been evaluated, any remaining orders are labelled as Unknown or Direct. These are genuine cases where no trackable touchpoint exists, typically caused by privacy-focused browsers, VPNs, or customers who typed your URL directly without using a discount code. Most brands see 70-80%+ attribution coverage after the full waterfall, meaning only a small percentage of orders remain truly unattributed.Need help? Contact our team or book a demo.