PMax: Table Tops — Campaign Analysis
Summary
The account’s best PMax campaign and the only one still enabled. 4.12x blended ROAS across 22 days with 19.3 conversions. Channel data confirms PMax correctly allocated 98% of spend to Search, with negligible Display/YouTube waste. However, revenue dried up completely after Jan 28 (12 days of £0 revenue despite continued spend), which is likely attribution lag on a small-data campaign rather than a genuine performance collapse.
Campaign Configuration
| Setting | Value |
|---|---|
| Campaign ID | 77 |
| Name | PMax: Table Tops (SC) |
| Type | Performance Max |
| Bidding strategy | MAXIMIZE_CONVERSION_VALUE |
| Daily budget | £60 |
| Target ROAS | Not captured (NULL) |
| Status | ENABLED |
| First data | Jan 19, 2026 |
Channel Breakdown (confirmed via segments.ad_network_type)
| Channel | % Spend | Impressions | Clicks | Cost | CPC | Conv | Revenue | ROAS |
|---|---|---|---|---|---|---|---|---|
| SEARCH | 98.3% | 32K | 801 | £689 | £0.86 | 19.3 | £2,892 | 4.20x |
| CONTENT (Display) | 0.9% | 2K | 20 | £6 | £0.31 | 0 | £0 | 0.00x |
| YOUTUBE | 0.5% | 445 | 4 | £4 | £0.93 | 0 | £0 | 0.00x |
| SEARCH_PARTNERS | 0.2% | 308 | 5 | £2 | £0.33 | 0 | £0 | 0.00x |
| GMAIL | 0.1% | 165 | 1 | £1 | £0.52 | 0 | £0 | 0.00x |
| TOTAL | 100% | 35K | 831 | £701 | £0.84 | 19.3 | £2,892 | 4.12x |
All 19.3 conversions came from Search. Non-Search channels consumed only 1.7% of budget (£12) — negligible waste compared to Knife Rack’s 15.2%.
Why Table Tops avoids the Display trap
MAXIMIZE_CONVERSION_VALUE (Table Tops) vs MAXIMIZE_CONVERSIONS (Knife Rack) makes a critical difference. MAXIMIZE_CONVERSION_VALUE optimises for revenue, not conversion count — so it has no incentive to buy cheap Display clicks that don’t produce revenue. MAXIMIZE_CONVERSIONS just wants more conversions, so cheap Display clicks that occasionally trigger micro-conversions look attractive to the algorithm.
The £60/day budget is also better calibrated. Natural Search demand roughly fills it, so there’s less leftover budget for the algorithm to dump into Display.
Performance Data
Daily Breakdown
| Date | Channel | Impr | Clicks | Cost | Conv | Revenue | ROAS |
|---|---|---|---|---|---|---|---|
| Jan 19 Sun | SEARCH | 2,020 | 53 | £41 | 1.0 | £179 | 4.37x |
| Jan 20 Mon | SEARCH | 1,541 | 39 | £36 | 2.0 | £220 | 6.11x |
| Jan 21 Tue | SEARCH | 1,632 | 48 | £41 | 2.0 | £209 | 5.10x |
| Jan 22 Wed | SEARCH | 1,453 | 37 | £29 | 0 | £0 | 0.00x |
| Jan 23 Thu | SEARCH | 1,448 | 40 | £33 | 2.0 | £248 | 7.52x |
| Jan 24 Fri | SEARCH | 1,559 | 35 | £30 | 2.0 | £228 | 7.60x |
| Jan 25 Sat | SEARCH | 1,549 | 37 | £28 | 1.0 | £218 | 7.79x |
| Jan 26 Sun | SEARCH | 1,757 | 47 | £41 | 2.0 | £368 | 8.98x |
| Jan 27 Mon | SEARCH | 1,629 | 42 | £30 | 2.0 | £428 | 14.27x |
| Jan 28 Tue | SEARCH | 1,566 | 46 | £41 | 3.3 | £594 | 14.49x |
| Jan 29 Wed | SEARCH | 1,031 | 29 | £28 | 1.0 | £0 | 0.00x |
| Jan 30–Feb 9 | SEARCH | ~16K | ~348 | £311 | 1.0 | £0 | 0.00x |
The “collapse” after Jan 28
The audit flagged Table Tops as “collapsing” — 6.57x ROAS in the Jan 19 week to 0.25x in Feb 2–8. The channel data shows this isn’t a channel-mix problem (98% Search throughout). Three factors explain it:
1. Low data volume. 19.3 total conversions in 22 days. That’s less than 1 per day. A few days without a conversion is statistically normal, not a signal of collapse.
2. Attribution lag. Google’s click-based conversion attribution can take 7–30 days. Clicks from Jan 30 onwards may not have finished attributing. The recent weeks always look worse than they really are — this is a known artefact with any conversion-optimised campaign.
3. The campaign is only 22 days old. PMax’s algorithm needs ~6 weeks to fully optimise. The first 3 weeks showed strong performance (19.3 conversions), and the algorithm was still in learning phase for the remaining period.
Conversion verification
All 19.3 conversions are confirmed purchases via “Analyzify - Purchase” conversion action (not add-to-carts). Average conversion value: £150 — consistent with table top pricing (£100–200 range). The ROAS figures are genuine.
Device Breakdown (30 days, Jan 11 – Feb 9)
| Device | Spend | % Spend | Clicks | CPC | Conv | Revenue | ROAS |
|---|---|---|---|---|---|---|---|
| Desktop | £417 | 59.5% | 365 | £1.14 | 8.3 | £1,495 | 3.59x |
| Mobile | £262 | 37.4% | 440 | £0.60 | 10.0 | £1,360 | 5.19x |
| Tablet | £23 | 3.3% | 26 | £0.87 | 1.0 | £37 | 1.63x |
| Connected TV | £0.03 | <0.1% | 0 | — | 0.0 | £0 | 0.00x |
Key findings:
- Mobile outperforms desktop on ROAS (5.19x vs 3.59x) at nearly half the CPC (£0.60 vs £1.14). For a ~£150 AOV product this is somewhat unexpected — table tops are a considered purchase you’d expect to convert better on a larger screen.
- Mobile gets more clicks and more conversions (440 clicks, 10.0 conv) than desktop (365 clicks, 8.3 conv) despite lower spend. Mobile traffic is significantly cheaper and converts better for this product category.
- Desktop still healthy — 3.59x ROAS is well above breakeven. Both devices are profitable.
- Connected TV appeared — £0.03, negligible, but indicates PMax is testing video placements. Worth monitoring if this grows.
Caveat: 10 vs 8.3 conversions is a small sample. The mobile/desktop ROAS difference (5.19x vs 3.59x) could narrow with more data. Directionally useful, not conclusive.
Analysis
Strengths
- Clean channel allocation: 98% Search is excellent for PMax. MAXIMIZE_CONVERSION_VALUE correctly avoids Display junk placements.
- Strong CPC: £0.86 on Search — reasonable for table top product searches.
- High AOV: £150 average conversion value gives healthy margin after ad cost (~£36 cost per conversion).
- Budget efficiency: £60/day is well-calibrated to natural demand. No budget waste.
Concerns
- Too few conversions to evaluate properly. 19.3 in 22 days is not enough data. Need 6–8 weeks minimum.
- Revenue gap after Jan 28: 12 days of £0 revenue on Search. If this persists beyond attribution lag (i.e., by mid-February the late-Jan clicks still show £0), the campaign may have genuinely stalled.
- Cannibalization limited but unknown: PMax has limited search term visibility through Google’s API — only a subset of queries are exposed. We can’t fully assess whether PMax Search is winning auctions that Shopping Catch All would have captured. Table tops are in the >£20 range, so they’re eligible for the Catch All campaign.
What we can’t see
| Question | Why it matters | Data needed |
|---|---|---|
| Full PMax search terms | Google only exposes a subset — cannibalization with Shopping Catch All can’t be fully assessed | API limitation (no fix) |
| Did attribution fill in for late Jan? | Determines if “collapse” is real or lag | Re-query in 2–3 weeks |
| Which table top products convert? | Product mix affects sustainability | Product-level PMax data |
| Was a config change made? | Could explain the performance shift | Campaign config history (Phase 1) |
Verdict
Keep running, but monitor closely. The channel data is clean (98% Search), the ROAS on Search is strong (4.20x), and the AOV supports paid acquisition. The “collapse” is most likely attribution lag on a low-volume campaign.
Review criteria at 6 weeks (early March):
- If cumulative ROAS remains above 3x with attribution caught up → healthy campaign, consider increasing budget
- If late-Jan clicks never attribute conversions → genuine performance decline, investigate search terms and product mix
- If search term data reveals heavy cannibalization of Shopping Catch All → consider whether PMax adds incremental value
Comparison with Knife Rack
| Metric | Table Tops | Knife Rack |
|---|---|---|
| Bidding strategy | MAXIMIZE_CONVERSION_VALUE | MAXIMIZE_CONVERSIONS |
| Search % of spend | 98.3% | 84.8% |
| Display % of spend | 0.9% | 12.2% |
| Search ROAS | 4.20x | 2.38x |
| Display conversions | 0 | 0 |
| AOV | £150 | £53 |
| Cost per conversion | £36 | £26 |
| Margin after ad cost | ~£100+ | ~£10-15 |
| Verdict | Viable | Not viable (correctly paused) |
The key differences: MAXIMIZE_CONVERSION_VALUE avoids Display waste, higher AOV provides margin buffer, and the budget is better calibrated.
Related Documents
./pmax-knife-rack-analysis.md— Knife Rack PMax analysis (paused, Display waste pattern)../../shopify-app/docs/ad-platform/working-plan.md— Search term sync (Phase 2), campaign config history (Phase 1)../../../market-intelligence.md— PMax channel-level reporting availability, account-level placement exclusions