> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vortexiq.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# CPC Spike Detection, Google Ads

> CPC Spike Detection for Google Ads accounts. Tracked live in Vortex IQ Nerve Centre.

**Metrics type:** [Supporting Metrics](/nerve-centre/overview#metrics-types-explained)  •  **Category:** [Ad Platform](/nerve-centre/connectors#connectors-by-type)

## At a glance

> **Detects sudden, sharp increases in CPC at the keyword level.** More aggressive than `gads_cpc_anomaly` (which uses 2σ threshold). This card fires when any keyword's CPC doubles vs the 30-day baseline. **CPC doubling without conversion-rate change halves ROAS instantly.** The card protects the budget against runaway bidding caused by Smart Bidding misfires, competitor entry, or Quality Score collapse on a specific keyword.

|                        |                                                                                                                                                 |
| ---------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------- |
| **What it counts**     | Detects when any keyword's current 24h CPC exceeds 2x its 30-day baseline. Reports the affected keyword and the current vs baseline CPC values. |
| **Sample basis**       | Per-keyword Google Ads spend and click data, real-time.                                                                                         |
| **Sampling threshold** | n/a (full data).                                                                                                                                |
| **Bot traffic filter** | Google Ads invalid-click filter.                                                                                                                |
| **Time zone**          | Account time zone.                                                                                                                              |
| **Time window**        | `RT` (rolling 24h vs 30D baseline)                                                                                                              |
| **Alert trigger**      | `keyword_cpc > 2 × keyword_baseline_cpc`                                                                                                        |
| **Sentiment key**      | `gads_cpc_spike` (alert variant)                                                                                                                |
| **Roles**              | owner, marketing, finance                                                                                                                       |

## Calculation

```
gads_cpc_spike fires when, for any keyword:
  current_24h_cpc > 2 × baseline_30d_cpc
  AND keyword has at least 50 clicks in baseline period (signal threshold)
```

The 50-click signal threshold prevents false positives on low-volume keywords where small spend variations produce large percentage swings.

## Worked example

A UK-based BC store, CPC spike detection reading on Wednesday 15 May 26.

| Keyword            | 30D baseline CPC | 24h CPC | Multiplier | Status          |
| ------------------ | ---------------: | ------: | ---------: | --------------- |
| `garden hose 30m`  |            £1.50 |   £1.62 |      1.08x | Normal          |
| `bbq charcoal`     |            £0.85 |   £1.95 |  **2.29x** | **Spike alert** |
| `outdoor cushions` |            £1.20 |   £1.34 |      1.12x | Normal          |
| `lawn fertiliser`  |            £0.95 |   £1.05 |      1.11x | Normal          |
| `patio heater`     |            £1.80 |   £4.20 |  **2.33x** | **Spike alert** |

**Two CPC spikes detected:**

1. **`bbq charcoal` jumped from £0.85 to £1.95.** Likely cause: BBQ-season demand surge plus competitor entry. Multiple advertisers competing for seasonal high-intent queries simultaneously.

2. **`patio heater` jumped from £1.80 to £4.20.** Likely cause: cold-weather forecast triggering competitor bid increases. Patio heaters are weather-sensitive; a forecast of cold spring evenings drives bid pressure across the category.

What the spike detection is telling us:

1. **Seasonal demand surges trigger CPC spikes that Smart Bidding may chase past the profitability point.** At £4.20 CPC × 100 clicks = £420/day on patio heater alone. If conversion rate is unchanged, the cost-per-acquisition jumps proportionally.

2. **Recommended response per spike:**
   * **`bbq charcoal`**: confirm BBQ Charcoal Pro inventory is healthy (cross-reference `bc_low_stock`); if so, accept the higher CPC because seasonal demand justifies it. Conversion volume should rise alongside CPC.
   * **`patio heater`**: cross-check; if patio heater is going OOS or seasonally winding down, **pause this keyword temporarily** rather than chase the spike.

3. **The Smart Bidding angle.** Smart Bidding will chase rising auctions when it sees rising conversion likelihood. **If conversion rate doesn't keep up, Smart Bidding can dig a CPA hole quickly.** Cap target-CPA settings so Smart Bidding can't bid above breakeven.

4. **Brand vs non-brand consideration.** Brand keyword spikes are rare (low competition, high QS); non-brand keyword spikes are common during seasonal events. The default config excludes brand keywords from spike detection to reduce noise.

5. **Recommended action workflow:**
   * **Hour 1**: Identify the affected keyword(s).
   * **Hour 2**: Check inventory and conversion rate for the affected products.
   * **Day 1**: Decide per keyword: accept the higher bid (if conversion volume justifies), pause keyword (if conversion can't keep up), or set bid cap (if you want sustained presence at controlled cost).
   * **Day 2-3**: If multiple keywords spike simultaneously, audit Smart Bidding strategy and target settings.

## Sibling cards merchants should reference together

| Card                                                                                  | Why merchants reach for it                  |
| ------------------------------------------------------------------------------------- | ------------------------------------------- |
| [`gads_cpc_anomaly`](/nerve-centre/kpi-cards/google-ads/cpc-anomaly)                  | Less aggressive 2σ variant.                 |
| [`gads_alert_cpc_spike`](/nerve-centre/kpi-cards/google-ads/cpc-spike-alert)          | Alert routing.                              |
| [`gads_quality_score`](/nerve-centre/kpi-cards/google-ads/quality-score-distribution) | Quality Score; major CPC driver.            |
| [`gads_cpa`](/nerve-centre/kpi-cards/google-ads/gads-cpa)                             | Cost per acquisition; downstream effect.    |
| [`gads_roas`](/nerve-centre/kpi-cards/google-ads/roas)                                | ROAS; collapses if CPC outpaces conversion. |
| [`gads_total_spend`](/nerve-centre/kpi-cards/google-ads/total-spend)                  | Total spend impact.                         |

## Reconciling against the vendor's own dashboard

**Where to look in Google Ads:** Reports → Keywords with sort by CPC; Auction Insights for competitive context.

**Why our number may differ:**

| Reason                                                                                        | Direction                         | What to do                          |
| --------------------------------------------------------------------------------------------- | --------------------------------- | ----------------------------------- |
| **Real-time vs reported.** Google Ads reports lag 1-3 hours; this card uses real-time stream. | Vortex IQ may show signal earlier | n/a; earlier is better.             |
| **Brand keyword classification.** Manual; not natively flagged.                               | Variable                          | Configure per-keyword in Vortex IQ. |

**Cross-connector reconciliation:** complement with Auction Insights for competitive context, and `gads_quality_score` for Quality Score detail.

## Known limitations / merchant FAQs

**Q: Why is the threshold 2x rather than 1.5x?**
2x is the threshold for "structurally meaningful" spike that warrants action. 1.5x produces alert fatigue from normal variance. The 2σ statistical threshold (`gads_cpc_anomaly`) catches more subtle anomalies; this card catches the runaway cases.

**Q: A keyword spiked but conversions are also up. Should I pause?**
No, accept the higher CPC if conversion rate × AOV × margin still produces positive contribution. Smart Bidding chases rising auctions correctly when conversion likelihood is rising. The spike is a signal of demand, not a problem.

**Q: A keyword spiked and conversions are flat. Should I pause?**
Yes, or at least cap the bid. Rising CPC without rising conversion means Smart Bidding is misfiring, likely it's seeing a high-intent signal that doesn't translate to your store. Cap the keyword at the prior bid and observe.

**Q: How does this differ from `gads_cpc_anomaly`?**
That card uses 2σ statistical threshold (catches gradual creep); this card uses 2x absolute threshold (catches sudden doubling). The two complement each other: anomaly catches subtle changes, spike catches abrupt ones.

**Q: Brand vs non-brand handling, why exclude brand?**
Brand CPC is structurally £0.10-£0.50 with very tight variance. Even a 50% spike is a small absolute number (£0.20 to £0.30) and rarely indicates a real problem. Non-brand spikes are operationally meaningful.

**Q: We use Performance Max, does this card work?**
Partially. Performance Max doesn't expose per-keyword CPC at the same granularity. The card can detect campaign-level CPC spikes but not the per-keyword detail available in standard Search campaigns.

**Q: How do we set keyword-level bid caps?**
In Google Ads: Campaign → Settings → Bidding → Bid limits. Set max-CPC at the level above which the keyword becomes unprofitable. Vortex Mind can recommend bid-cap values based on contribution-per-conversion math.

**Q: Spike alerts firing 5x/week, too noisy?**
Likely the threshold is too aggressive for your account size. Adjust to 2.5x or 3x in profile settings. Alternatively, exclude long-tail keywords from spike detection (they have natural variance from low click volumes).

***

### Tracked live in Vortex IQ Nerve Centre

*CPC Spike Detection* is one of hundreds of KPI pulses Vortex IQ tracks across Google Ads and 70+ other ecommerce connectors. Nerve Centre runs the detection layer; Vortex Mind investigates the cause when something moves; Ask Viq lets you interrogate any number in plain English.

[Start for free](https://app.vortexiq.ai/login) or [book a demo](https://www.vortexiq.ai/contact-us) to see this metric running on your own data.