Keywords Quality Monitoring on Google Ads
Summary
Daily n8n and LLM automation monitoring Google Ads keyword quality metrics to diagnose underperformance, protect ROI, and proactively optimize ad relevance.
Background
In digital advertising, a campaign’s cost-per-click and ad positioning are heavily dictated by Google's internal quality metrics. Empirical research on search engine advertising has demonstrated that higher keyword and landing page quality—core components of Google's Quality Score—directly lower the advertiser's cost-per-click (CPC) and can increase conversion rates by as much as 22.5%. When Quality Scores drop, ad costs spike, directly damaging campaign ROI. Across industries like e-commerce and B2B SaaS, companies lose substantial budgets because they fail to catch declining keyword health early. Manually reviewing diagnostic metrics across thousands of active keywords is operationally impossible for lean marketing teams.
This project emerged to bridge this gap, taking inspiration from automated health-monitoring systems in software engineering—creating an automated guardrail that flags degrading keyword performance before it drives up acquisition costs.
Goals
By implementing this project, we aim to achieve the following:
Automate Quality Diagnostics
Pull daily keyword quality metrics directly via the API to eliminate manual data auditing.
Identify Root Causes of Underperformance
Instantly isolate whether a low Quality Score is driven by poor ad relevance, a weak landing page, or low expected CTR.
Enable Actionable Insights
Use AI to translate raw categorical API data into concrete, proactive marketing recommendations.
Optimize Ad Spend Efficiency
Proactively flag or pause keywords with low quality scores to prevent inflated cost-per-click (CPC) penalties.
Approach
To build a proactive keyword quality monitoring system for Google Ads, we evaluated three primary options: standard manual dashboard reviews, native Google Ads automated rules, and an intelligent automation, LLM-driven diagnostic workflow. Manual dashboards are unscalable for daily, granular reviews. While native automated rules can filter for specific categorical metrics, they are rigid and only execute basic binary actions; they cannot synthesize multiple variables into a cohesive, human-readable diagnostic strategy.
The best option is an automation with LLM-driven diagnostic workflow orchestrated by n8n. By utilizing an LLM featuring advanced logical reasoning capabilities, the AI acts as an automated expert media analyst. When n8n fetches the daily diagnostic data from the Google Ads API (specifically Quality Score, Ad Relevance, Landing Page Experience, and Expected CTR), it hands this categorical matrix to the LLM. The LLM evaluates the unique combination of these metrics to pinpoint exactly why a keyword is underperforming and outputs a concise, human-friendly recommendation. This approach ensures marketing teams get notified early about degrading performance, allowing them to respond proactively before budgets are wasted. Furthermore, once the automation is set up, it is incredibly easy to maintain and highly cost-effective, with ongoing overhead limited strictly to minimal server hosting and API usage fees.
Scalability
This setup is configured for daily monitoring where the n8n instance is hosted with a minimum setup utilizing an "inherited" Simple Memory. This framework works best for any businesses since the automation wont take high resource of CPU or memoery. This automation runs within a Private VPS which costs (outside the LLM requirements) of approximately USD $1.7/month, which applies for 1 CPU & 1GB RAM.
This current configuration is specifically designed to handle Click to Whatsapp (CTWA) campaigns that drive users directly to a WhatsApp conversation from an active advertisement. Other alternative marketing campaigns may require unique adjustments due to the distinct tracking payloads passed in native CTWA elements.
For scaling up to multiple account daily automation & operations (particularly for agency), the workflow adapts exceptionally well with a small adjustment. Instead of running them all at once, we can add a loop and time-wait to maintain the process in a low memory. Additional Javascript code/Input for multiple channels target is also required to prevent sending information to the incorrect channel
Implementation Workflow
1. Prepare Google Ads Information
Prepare Google Ads information, including Google Ads Account ID & Google Ads Developer Token.
Ensure the Google Ads account (not the manager) has been included in the MCC account.
Google Dev Token can only be generated by Google Ads MCC (Manager Account).
In addition, the developer token at least need to be Basic level.
2. Create an automation flow on n8n
Create an HTTP request to Google Ads using the Google Ads Account ID, Dev Token, and MCC Account ID.
Query the keywords data including: Date, Campaign, Ad Group, Keyword, and Quality metrics including: Quality Score, Ad Relevance, Landing Page Experience, and Expected CTR.
Store this information to your database.
Call today’s and yesterday’s data, feed it into AI Agent.
Set system prompt to compare today’s and yesterday’s data and extract insight with the data.
3. Connect to Channel Output & Define Time Reminder
Connect the AI Agent to your preference channel output.
Connect the HTTP request to the Time Schedule for regular report.
4. Test & Publish the workflow
Test the workflow and evaluate the system prompt based on the preference.
Publish the workflow to the production.
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Requirements
- Automation Infrastructure An n8n instance to schedule daily API calls, handle conditional routing, and trigger notifications based on keyword status.
- AI & Diagnostic Engine An LLM API account to analyze the combination of categorical quality scores and output structured recommendations.
- Storage & Documentation A centralized spreadsheet or database (e.g., Google Sheets) to log daily keyword performance snapshots and track quality score trends over time.
- Google Ads Developer Token Valid OAuth2 credentials and a Google Ads Developer Token to authorize secure, read-only requests to your advertising accounts.
- Messaging Interface Endpoint A connected chat endpoint (such as a private Telegram bot, Discord bot, or Slack App) to serve as your communication interface.
References
-
Empirical Analysis of Search Engine Advertising:
Management Science, Sponsored Search in Electronic Markets. Academic research demonstrating how higher keyword and landing page quality directly lower advertiser cost-per-click and positively impact conversion rates. -
Google Ads API Fields:
Google Developers, ad_group_criterion.quality_info Resource Field Reference. Official technical documentation detailing the specific data structure for querying the categorical diagnostic metrics used in search ad auctions. -
SEM Core Concepts:
Industry Insights, The Mechanics of Ad Auction Quality Score and CPC Penalties. Overview explaining the fundamental mechanics of how Google penalizes poor ad relevance and its direct correlation to budget wastage. -
Quality Score Fundamentals:
Google Ads Help, About Quality Score for Search Campaigns. Comprehensive guide explaining how Google calculates the 1-10 quality score based on the combined matrix of expected clickthrough rate, ad relevance, and landing page experience.