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Sample PPC Waste Audit — UK Mid-Market Client
5-month YTD analysis · period and identifiers anonymised · prepared from live GA4 reports
Client sector: UK national organisation
Analysis period: 5 months · period anonymised
12 Key Events configured
~76 total event names firing
📌 Composite case study. Based on a real audit methodology run by AI Guy In Your Corner. Numbers scrambled (±15–25%), event names generalised, date range and identifiers removed. No identification with any specific organisation implied. Real audits delivered under NDA.
Executive Summary
Active Users (YTD)
~247K
Step-down from early Month 4
New Users (YTD)
~233K
Month 3 peak: ~60K first visits
Page Views (YTD)
~1.69M
~4.6M total events
Total Key Events
~11,287
Concentrated in Month 3; −40% Month 4
Engagement Rate
64.9%
Stable — engagement intact
Avg Engagement Time
4m 50s
Stable
⚠ Three things changed at the end of Month 3 / start of Month 4
- Audience step-down: daily active users halved from ~4–5K/day (Months 1–3) to ~2–3K/day (Months 4–5).
- Conversion collapse: almost every key event peaked in Month 3 then dropped sharply in Month 4 (transactions −38%, revenue events −29%, signup_b −67%).
- Tracking break:
form_submit_a went from ~983 events in Month 3 to literally zero in Month 4, then partially recovered to ~243 in Month 5 — almost certainly a tag/GTM issue, not real behaviour.
Because user-engagement metrics (engagement rate, session duration) stayed stable, the drop looks more like a
tracking/campaign/site change at the Month 3→4 boundary than a real audience collapse.
1. Site-wide Traffic Trend
Active Users / First Visits — Monthly
first_visit dropped from ~60K in Month 3 to ~34K in Month 4 (−43%). Month 5 on pace for ~32K. Engagement metrics held steady — meaning the visitors who do arrive are still engaged.
2. Lead Acquisition (Custom Channel Grouping)
Total New Leads — Monthly
Month 2 peak (~172), then dropping each month. Month 5 on pace for ~103.
Leads by Channel — Monthly
Email is the standout collapse: ~49 in Month 2 → ~7 in Month 4 (−85%).
3. Primary Landing Page Performance
/landing-page-a/ — Monthly Page Views
YTD: ~71K views · ~14K active users · 4.96 views per user · ~190K events · 89.2% engagement rate.
Peak Month 2 (~18.6K) → dropped −23% in Month 3 → further softening. The landing page weakened a month earlier than the wider site step-down.
4. Key Events — Month-by-Month Performance
The 12 Key Events configured in GA4
transactions
revenue_events
form_submit_a
resource_download
signup_b
signup_c
content_engagement
paid_search_thankyou
newsletter_signup (0)
lead_magnet_free (0)
conversion_event_transaction (0)
close_convert_lead (0)
qualify_lead (0)
5 of the 12 Key Events have zero data YTD. They are configured as conversions but the tags are not firing — needs a tagging/GTM audit.
Full Key Events Breakdown — Month 1 to Month 5
| Key Event | M1 | M2 | M3 | M4 | M5 (partial) | YTD | Status |
| transactions | 592 | 634 | 684 | 425 | 277 | ~2,612 | Peak M3 · −38% M4 |
| revenue_events | 533 | 589 | 783 | 558 | 258 | ~2,721 | Peak M3 · −29% M4 |
| form_submit_a | 2,172 | 1,744 | 983 | 0 | 243 | ~5,142 | ⚠ TRACKING BREAK M4 |
| resource_download | 1,115 | 1,408 | 676 | 975 | 740 | ~4,914 | V-shape recovery |
| signup_b | 83 | 85 | 162 | 53 | 11 | ~394 | Peak M3 · −67% M4 |
| signup_c | 13 | 15 | 25 | 23 | 17 | ~93 | Holding |
| content_engagement | 55 | 44 | 58 | 39 | 25 | ~221 | Peak M3 · −33% M4 |
| paid_search_thankyou | 13 | 15 | 25 | 23 | 18 | ~94 | Holding (Paid Search) |
| newsletter_signup | 0 | 0 | 0 | 0 | 0 | 0 | Not firing |
| lead_magnet_free | 0 | 0 | 0 | 0 | 0 | 0 | Not firing |
| conversion_event_transaction | 0 | 0 | 0 | 0 | 0 | 0 | Not firing |
| close_convert_lead | 0 | 0 | 0 | 0 | 0 | 0 | Not firing |
| qualify_lead | 0 | 0 | 0 | 0 | 0 | 0 | Not firing |
Transactions — Monthly
Month 3 peak 684, then Month 4 drops to 425 (−38%). Month 5 on pace ~460.
Revenue Events — Monthly
Rising trend M1–M3 (+47%), then sharp Month 4 drop (−29%). Month 5 on pace ~430.
Form Submit A — Monthly
⚠ Month 4 = 0 events. Declining trend M1–M3 then full break in Month 4. Month 5 partial recovery (~243).
Resource Download / Signups B & C — Monthly
signup_b collapses (162 → 53 → 11). signup_c holds flat. resource_download recovers in Month 4.
All Active Key Events — Indexed to Month 1 (M1 = 100)
Indexing each event to its Month 1 value makes the universal Month 4 drop unmistakable.
Almost every event tracks together — typical of a site/tracking/campaign-level change rather than independent product-level shifts.
5. Channel Performance — Where Conversions Come From
Sessions by Channel (YTD)
Key Events by Channel (YTD)
Channel Efficiency — Volume vs Conversion Rate
| Channel | Users | Key Events | Share of KE | User → KE rate | Insight |
| Organic Search | ~138K | ~1,853 | 16.43% | 0.97% | Traffic-rich, low-converting |
| Direct | ~56,700 | ~4,455 | 39.48% | 6.74% | Biggest absolute converter |
| Cross-network | ~18,000 | ~1,007 | 8.92% | 4.17% | Decent contribution |
| Email | ~15,600 | ~1,623 | 14.39% | 5.75% | Strong but collapsing |
| Organic Social | ~6,500 | ~79 | 0.70% | 0.92% | Negligible |
| Paid Search | ~6,000 | ~1,338 | 11.86% | 16.28% | ⭐ Best ROI — scale this |
| Referral | ~5,650 | ~307 | 2.72% | 3.61% | Steady |
| Paid Social | ~2,540 | ~35 | 0.31% | 0.74% | Underperforming |
| Unassigned | ~2,160 | ~326 | 2.89% | 10.14% | UTM hygiene issue |
| Organic Shopping | ~1,400 | ~255 | 2.26% | 11.89% | ⭐ Highly efficient |
Paid Search converts visitors at 16.3% — by far the most efficient channel. Organic Shopping at 11.9% is second. Both small in volume → big scaling opportunity.
Organic Search brings in over half the users but converts only 0.97% — large optimisation opportunity.
Revenue Events by Channel — Where the Money Comes From
Email drives 38% of all revenue events (~1,037 of ~2,721 YTD) — by far the biggest converting channel.
This is why the email-channel collapse Month 2 → Month 4 (49 → 7 leads, −85%) is so consequential to overall revenue.
6. The Month 4 Inflection — What Likely Happened
Multiple signals all point to a change at the Month 3 → Month 4 boundary
| Signal | Pre-M4 (M1–M3) | Post-M4 | % Change | Likely Cause |
| Daily active users | ~4–5K/day | ~2–3K/day | ~−50% | Traffic source / campaign pause |
| first_visit (M3 → M4) | ~60K | ~34K | −43% | Same — new visitor flow halved |
| form_submit_a (M3 → M4) | 983 | 0 | −100% | Tracking break — tag broke |
| transactions (M3 → M4) | 684 | 425 | −38% | Real conversion drop (real or tracking) |
| revenue_events (M3 → M4) | 783 | 558 | −29% | Email channel weakness |
| signup_b (M3 → M4) | 162 | 53 | −67% | Campaign-specific collapse |
| Email leads (M2 → M4) | 49 | 7 | −85% | Email cadence / campaign change |
| Engagement rate | ~65% | ~65% | Flat | Visitors still engaged → not a UX issue |
Diagnostic hypothesis
Because
engagement metrics held steady but acquisition + conversions both collapsed simultaneously across nearly all channels, the most likely explanations (in order) are:
- GTM / GA4 tagging change at the Month 3→4 boundary — supports the
form_submit_a zero and the broad multi-event drop.
- Major paid-media pause or campaign end at end of Month 3 — would explain user halving and email/cross-network slump.
- Site change / redesign deployed at the Month 3→4 boundary that broke event firing on certain pages.
- Q2 seasonal period — the timing aligns with a known Q2 seasonal dip in this sector, would explain a temporary dip but not the sustained Month 5 numbers.
7. Recommendations
🔧 Immediate (this week)
- Audit GTM change history at the Month 3 → Month 4 boundary — especially anything touching
form_submit_a.
- Fix the 5 non-firing Key Events:
newsletter_signup, lead_magnet_free, conversion_event_transaction, close_convert_lead, qualify_lead. They’re configured as conversions but tags aren’t firing.
- Reconcile backend (CRM / commerce platform) registration numbers for Month 4 against GA4 — confirms whether the drop is real or purely tracking.
- Review the custom channel grouping used in the Lead Acquisition report — it shows 0 key events while the default report shows ~11K. Mapping is broken.
📈 Strategic (this month)
- Scale Paid Search — 16.3% user→KE rate is best-in-class. Highest-leverage channel to invest in.
- Reinvest in Email — 38% of revenue events originate here, and the channel collapsed M2→M4. Audit cadence, deliverability, and any campaign pause.
- Improve Organic Search conversion — 55% of users but 0.97% conversion rate. Add CTAs/lead capture to high-traffic content pages.
- Tag the landing page conversion —
/landing-page-a/ fired ~190K events but 0 marked Key Events. A page-view-based conversion would fix attribution.
- Fix UTM hygiene — ~2,160 users / ~326 KEs in “Unassigned” means traffic sources aren’t being tagged on inbound links.
Appendix — All Captured Data Points
| Metric | M1 | M2 | M3 | M4 | M5 (partial) | YTD |
| first_visit | ~57,400 | ~61,650 | ~60,150 | ~34,225 | ~19,650 | ~233,075 |
| scroll (YTD only) | — captured monthly differently — | ~188K |
| Landing page views | ~15,600 | ~18,650 | ~14,350 | ~13,000 | ~9,565 | ~71,165 |
| Total leads | ~160 | ~172 | ~122 | ~83 | ~62 | ~599 |
| Email leads | ~19 | ~49 | ~15 | ~7 | — | ~90 |
| Organic Search leads | ~51 | ~49 | ~36 | ~39 | — | ~175 |
| Direct leads | ~52 | ~45 | ~46 | ~22 | — | ~165 |
| Paid Search leads | ~3 | ~8 | ~6 | ~3 | — | ~21 |
| Cross-network leads | ~12 | ~11 | ~15 | ~4 | — | ~42 |