Marketing reports often stop at the form submission. That can make a campaign with many poor enquiries look better than one that brings a few customers who are ready to buy. To judge marketing spend, follow the path from visit to enquiry to qualified lead to sale. Start with a definition your sales team can apply consistently.
1. Agree on what counts as a qualified lead
Write down the minimum facts. For a local contractor, that might be an enquiry in the service area, for a service the company offers, with a realistic timeframe and a reachable person. For a SaaS business, it may be a company in the target segment with a use case and budget range. Do not call every chatbot opening, phone tap or newsletter signup a qualified lead.
Keep the first version simple: new enquiry, qualified, booked, won, lost. Add a reason for lost or unqualified leads so you can see whether the issue is targeting, offer, pricing or follow-up.
2. Give each campaign a readable source
Use consistent UTM tags on links you control, such as email, paid social and partner placements. Choose a naming convention before launching: source identifies the platform, medium identifies the channel type, and campaign identifies the initiative. Keep spelling and capitalization consistent, because Analytics can split near-identical values into separate rows.
Do not add UTMs to internal links. They can overwrite acquisition information. For ads with native auto-tagging, follow the platform integration rules. Record the final landing page and UTM pattern in a shared campaign sheet so the team can audit it later.
3. Track the actual enquiry event
In GA4, mark meaningful actions as key events. A successful form submission should fire after the form has been accepted, not simply when a button is clicked. Test one submission on desktop and mobile and verify it appears once. For calls, distinguish a phone link click from a connected call or booked job. For ecommerce, the purchase event is more useful than an add-to-cart event when you report revenue.
Our GA4 setup guide explains event setup. Keep consent and privacy requirements in mind, and avoid putting personal details in analytics event parameters or URLs.
4. Carry the source into a lead record
When someone enquires, save the original source and campaign in the CRM alongside the date, page or offer, service requested and status. Preserve the first source and the latest source if your tools support both. Do not let a later sales email erase the channel that introduced the customer.
Assign one person to review new enquiries and mark qualification with the agreed criteria. Without that step, the dashboard can report volume but not lead quality. A basic spreadsheet is enough for a small team if the process is followed every week.
5. Compare channels using the same funnel
For each channel, report spend, enquiries, qualified leads, booked calls or estimates, customers and revenue when known. Cost per qualified lead equals channel spend divided by qualified leads. Customer acquisition cost equals channel spend divided by new customers attributed under your chosen method. If a channel produced zero qualified leads, show that plainly rather than dividing by zero or inventing a rate.
Attribution is an estimate of influence. A customer may discover you through a social post, research through search, then type your URL directly. Different attribution rules assign credit differently. Pick a consistent method, record its limitations, and compare trends rather than claiming a single channel caused every sale.
6. Review the gaps before changing budget
- Check that each key event fires correctly and that lead records have a source.
- Look at the qualified share of enquiries, not just the enquiry count.
- Read reasons for disqualification and lost deals.
- Compare periods long enough for your sales cycle to complete.
- Improve the page, offer or follow-up process before assuming the channel failed.
When you can see the full funnel, marketing decisions become more specific. You can identify a campaign that brings the wrong buyer, a page that converts the right buyer, or a slow follow-up process that loses them after marketing has done its job. For AI assistant referrals in particular, pair this method with our AI search measurement guide.
Sources and further reading
See Google's guidance on GA4 key events, campaign URL tagging, and traffic source dimensions.
Frequently asked questions
What is the difference between a lead and a qualified lead?
A lead is an enquiry. A qualified lead meets the business criteria you define, such as service fit, location, timing and a reachable contact.
Should a phone number click count as a sale?
No. A tap is an interaction, not proof that a call connected or a customer bought. Track later call and sales outcomes when possible.
Can GA4 tell me exactly which channel caused a sale?
GA4 can report attributed paths and key events, but people use multiple touchpoints and some visits are not measurable. Keep the attribution method consistent and state its limits.