Setting up conversions (key events) in GA4

Part 3 covered events as GA4's universal data unit. Not every event represents a genuine business outcome worth optimizing toward — a "key event" (GA4's current term for what was previously called a "conversion") is a specific, deliberate designation marking which events actually matter for real decision-making.

Marking an existing event as a key event

Admin → Events → toggle "Mark as key event" on: purchase

Once an event like purchase (part 3's real, worked example) is already flowing into GA4, marking it as a key event doesn't change the underlying data at all — it makes that specific event available in conversion-focused reports, in attribution modeling (part 13), and as a target for Google Ads' Smart Bidding if the accounts are linked (part 14).

A real key event set for Bright Leaf Coffee

purchase           → the primary, revenue-generating key event
sign_up            → newsletter signup, a genuine secondary goal
begin_checkout     → a real, meaningful funnel-stage signal, even
                      though it isn't the final outcome

Three key events, each representing a genuinely distinct, real business outcome — not just any event that happens to occur frequently. begin_checkout specifically is worth marking even though it isn't a completed sale, since it's a strong, real signal of purchase intent, useful for the exploration funnel analysis covered in part 12.

A real key event set for GreenDesk

generate_lead      → the primary key event — a completed demo request
                      form, GA4's own recommended event name for this
                      exact scenario
book_demo_call     → a custom event if a separate, direct calendar-booking
                      step exists past the initial form

generate_lead is one of GA4's recommended event names (part 3) — using it exactly, rather than inventing a custom name, keeps GreenDesk's lead-gen tracking aligned with GA4's own built-in reporting and with Google Ads' own recommended conversion action naming when the two are eventually linked (part 14).

Why marking too many events as key events dilutes the real signal

Over-marked: page_view, scroll, session_start, click, video_start, AND
             purchase — all treated as equally important key events

If every event is a key event, none of them functions as a genuine, distinguishing signal of real business value — reports and automated bidding systems downstream (the Google Ads series' own Target CPA/ROAS guidance depends directly on a clean, meaningful conversion signal) end up optimizing toward a noisy mix that includes trivial, low-value interactions alongside genuinely important ones. A tight, deliberate key event list — the real, few outcomes that actually matter to the business — is what keeps this signal useful.

Key events vs. GA4's own automatically-suggested ones

GA4 sometimes auto-suggests marking certain frequent events as key events based on general usage patterns across many properties — worth reviewing each suggestion critically against the specific business's own real goals, rather than accepting every suggestion by default, since GA4's suggestion logic has no actual knowledge of what constitutes a meaningful outcome for this specific business.

Value: attaching real revenue or estimated worth to a key event

purchase: real value from the transaction itself (part 3's items parameter)
generate_lead: an assigned estimated value, since a lead has no direct
               transaction value at the moment it's captured — commonly
               set based on a known average lead-to-customer conversion
               rate and average deal size

GreenDesk's generate_lead event has no natural dollar value the way a purchase does — assigning a real, reasoned estimated value (even an approximate one, based on real historical lead-to-close rates) is what makes ROAS-style reporting and bidding optimization possible for a lead-gen business at all, rather than working purely from raw lead counts with no value signal attached.

Next: e-commerce tracking in full — Bright Leaf Coffee's actual purchase, revenue, and product-performance reporting, built out completely.