How to Build a Reliable eBay Web Scraper(Python)
Step-by-step guide to build a eBay web scraper using Python, proxies, requests & Playwright examples, proxy setup, scale tips, monitoring, and legal cautions.
Dec 3, 2025
Step-by-step uncover competitors’ keywords, ads, and gaps using Google tools and third-party helpers for better PPC performance.
Want to out-think your Google Ads competitors without paying for enterprise tools? This guide gives you the free Google tools + selective freemium helpers to use, the exact actions you can run now, and a safe method to estimate competitor spend (directional).

Who this guide is for
Core free tools: Google Ads Keyword Planner, Auction Insights, Ads Transparency Center, Google Analytics / Search Console.
Quick wins: Export 10 target keywords from Keyword Planner, run Auction Insights, screenshot competitor creatives in Ads Transparency Center, and inspect landing page UTMs.
Directional spend estimate: competitor_impr = total_impr × impression_share → clicks = competitor_impr × CTR → spend = clicks × CPC (present results as ranges).
Do this: Weekly (ads/creatives) and monthly (full audit).
Benefits include:
Keyword Opportunities: Discover untapped terms your rivals bid on, potentially lowering your CPC while increasing traffic.
Ad Copy Inspiration: Analyze what messaging resonates, like using numbers, social proof, or urgent CTAs, to improve your click-through rates (CTRs).
Budget Efficiency: Estimate competitors' spends to allocate yours smarter, avoiding oversaturated auctions.
Market Gaps: Spot weaknesses, such as poor landing pages or ignored remarketing, to differentiate your campaigns.
Forecast trends: Like more video/Performance Max activity—watch creatives.
Don't attempt to access private account data or scrape Google in violation of TOS. Aggregate publicly visible data and use official APIs where available (e.g., Google Ads API for authorized access). Avoid copying trademarked brand names in your ad creatives; instead, use insights to craft differentiated messaging. All methods here focus on ethical, public data aggregation to stay compliant.
1. Google Ads → Keyword Planner → export 10 target keywords (CSV).
2. Run incognito searches + Ad Preview for your keywords and note recurring advertisers.
3. In Google Ads, run Auction Insights for those keywords and note competitor Impression Share.
4. Visit Ads Transparency Center and save 2-3 competitor creatives.
5. Paste the CSV audit line (below) into Google Sheets and compute simple spend ranges.
Paste this CSV line into a new Google Sheet (File → Import → Paste) and split into columns:
Keyword,Your IS (%),Competitor,Comp IS (%),Top-of-page bid mid,CTR low,CTR mid,CTR high,Est Clicks low,Est Clicks mid,Est Clicks high,Est Spend low,Est Spend mid,Est Spend high,Ad Notes,Landing Page Notes,UTM,Suggested Test
"marketing automation",35,competitor.com,20,2.50,0.03,0.05,0.07,60,100,140,120,250,420,"free trial CTA; social proof","long form; slow mobile","utm_campaign=trial","Test trial CTA; speed up mobile"
Use filters to sort by Comp IS or Suggested Test priority.
6. Launch 3 small tests (ad copy, offer, landing-page) based on findings.
Do incognito searches (desktop & mobile) for 3–5 priority keywords. Record advertisers that appear repeatedly.
Use Ad Preview or iSearchFrom to simulate other locations/devices without personalization. If you need more accurate multi-location visibility (e.g., checking ads in different cities or countries), using a residential proxy helps you view unbiased Google Ads results from any region. This is especially useful for local businesses and ecommerce brands with geo-targeted competitors.
Result: 5–10 real competitors per keyword.
Quick Test Idea: Add one new competitor domain to your watchlist.
In Google Ads, open Auction Insights for each keyword and copy Competitor Impression Share and Position Above Rate into your sheet.
Go to Ads Transparency Center (adstransparency.google.com), search competitor domains, and save screenshots of 2–3 active ads (headlines, offers).
Result: Reliable auction metrics + ad examples.
Quick Test Idea: Tweak one headline based on a competitor's CTA.
Click competitor ads (incognito) and inspect: hero message, CTA, form fields (≤3 preferred), price/promo, trust badges, and mobile UX.
Run their page through PageSpeed Insights for mobile score and note speed issues.
Copy any UTMs you find into your sheet(they’re clues to campaign structure).
Result: 3 testable ideas (copy, offer, page speed).
Quick Test Idea: Optimize your page speed if theirs is faster.
You cannot find exact spend/CPA — these are private. But you can make a directional estimate and show it as a range.
Method:
1. Get total monthly eligible impressions from Keyword Planner.
2. Get Competitor Impression Share from Auction Insights.
3. Assume a CTR range (conservative: 3–7%).
4. Use CPC range from Keyword Planner top-of-page (low–high).
5. Compute ranges:
comp_impr = total_impr × comp_IS
clicks = comp_impr × CTR_range
spend = clicks × CPC_range
Digit-by-digit example:
Total eligible impressions = 10,000.
Competitor impression share = 20% → comp_impr = 10,000 × 0.20 = 2,000.
CTR (mid) = 5% → clicks = 2,000 × 0.05 = 100.
CPC mid = $2.50 → spend = 100 × $2.50 = $250.
Present as range using CTR 3–7% and CPC $2.00–$3.00 → clicks = 60–140 → spend = $120–$420. Always list the CTR/CPC assumptions.
Result: a budget benchmark (range) to guide bids and prioritization.
Quick Test Idea: Adjust bids on low-competition keywords.
Common UTM clues (not guaranteed):
| UTM example | Likely meaning |
| utm_source=g | |
| utm_medium=c | Campaign medium / search shorthand |
| utm_campaign=RLSA | Remarketing Lists for Search Ads |
| utm_term=exact:crm+software | Keyword + match type indicator |
| utm_content=promo_spring | Creative or promo variant |
Record patterns to infer brand vs non-brand focus, remarketing intensity, and geo splits. Use these to form tests (e.g., set up an RLSA if competitors use RLSA).
Result: Hypotheses for campaign structure and audience tests.
Quick Test Idea: Set up a simple RLSA if competitors use it.
Choose tests with fast feedback:
1. Ad copy test: run 2 new headlines inspired by a competitor’s winning angle (e.g., “Free trial”).
2. Offer test: match or beat a competitor promo for 48 hours to measure conversion lift.
3. Landing page test: reduce form fields or speed up mobile page to improve CVR.
Track results and iterate.
Result: Immediate experiments that move metrics.
Quick Test Idea: Launch one test in your Ads account today.
Shopping: Competitor shows −10% price + 4.3 stars → test matching price for 48 hrs and measure CVR lift.
SaaS: Competitor’s UTM utm_campaign=trial + short form → test a 3-field trial signup and compare conversion rate.
Daily: Only for aggressive scaling—major Impression Share drops, new top competitors, big CPC spikes.
Weekly: New creatives, promotional changes, Shopping feed updates.
Monthly: Full keyword list reconciliation, pivot budgets, landing page audits.
Trigger-based: If CTR or conversion rate drops, run immediate competitor checks.
Local business (one location): Prioritize Auction Insights (geo), local keywords, mobile creatives. Look for competitors using local extensions and store-specific offers. Use iSearchFrom (or Google Ad Preview) to emulate local searches without personalization.
E-commerce / Shopping: Inspect Google Merchant Center & Shopping results: product images, price promos, and ratings. Moat and Ads Transparency Center help for creatives used in display retargeting. Track competitor promo cadence (seasonal discounts) and align ad schedules. In 2025, analyze AI-recommended Shopping ads.
SaaS / B2B: Focus on reverse-engineering UTMs for lead sources; inspect landing-page forms and hidden offers (whitepapers, trials). Use Keyword Planner to prioritize high-intent terms (pricing, buy, trial).
Enterprise / Brand protection: Monitor brand-term bidding by competitors (brand protection). Use Auction Insights on brand keywords and set rules to protect brand SERP via defensive campaigns.
Core (free): Google Ads (Auction Insights, Keyword Planner, Ad Preview), Ads Transparency Center, Google Analytics, Search Console.
Supplement (freemium): SpyFu or SEMrush free reports (for historic ad copy; SEMrush free includes basic AI keyword suggestions as of 2025), Ubersuggest for quick keyword ideas, Moat for display creatives, Exploding Topics for budget overviews (permanently free for Google Ads competitor analysis, revealing ad spend focus by domain).
Automated: Use Google Sheets for scheduled exports (Keyword Planner + Auction Insights) → simple change detection (conditional formatting) to flag new competitors or IS drops.
Pro Tip: Search for "Google Ads competitor tracking sheet" or use the template above. If your monitoring workflow requires checking SERPs frequently or from multiple regions, pairing your process with a stable residential proxy prevents request blocking and ensures you see consistent, location-accurate ad results.
Pitfall: Treating freemium tool estimates as truth. → Fix: Report ranges and confidence levels (e.g., 85-90% accuracy per tool benchmarks).
Pitfall: Obsessing over spend numbers. → Fix: Focus on what they bid on (keywords), what messaging works, and gaps you can exploit.
Pitfall: Looking at randomized searches only once. → Fix: Search across locations, devices, and times; use Auction Insights for true auction-level data.
First-party data matters more: Cookie deprecation means you should lean on Analytics + server-side tracking.
AI bidding & PMax effects: Automated bidding can reduce CTR predictability. Use ranges in CTR assumptions and monitor outcome metrics, not just position.
Prediction (Tool evolution): Expect deeper, low-cost AI ad analysis features in tools; treat AI suggestions as hypotheses you still test against first-party results. For example, use free ChatGPT for ad copy ideation based on analyzed creatives.
Q: Can I get exact competitor spend/CPA?
A: No. Those are private. Use Auction Insights + CPC/CTR assumptions for directional estimates.
Q: How often should I run checks?
A: Weekly for hot niches; monthly for stable sectors.
Q: Which free tool is most reliable?
A: Auction Insights for auction-level reliability in auctions you participate in; Ads Transparency Center for creatives.
Start with Google’s free tools (Keyword Planner, Auction Insights, Ads Transparency Center, Analytics). Use freemium tools (SEMrush/SpyFu/Moat/Exploding Topics) only to supplement gaps or historical views. Focus on things you can change quickly: ad copy, offers, and landing-page experience. Present all competitive numbers as ranges and run small tests to validate hypotheses. Drive better results in a competitive 2026 market.
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