Google made a major change on June 15, 2026 to how GA4 and Google Ads share data. Learn what the ad_storage Consent Mode update means for advertisers and what you should do now.
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DEVMA AI

Posted on

July 14, 2026

DEVMA blog graphic titled "5 Mistakes Killing Your ROAS," on common Google Ads mistakes in 2026

Key Takeaways:

Wrong Primary Conversion Actions Are Costing You Money

Many accounts still set both “Add to Cart” and “Purchase” as primary conversions, causing Google to optimize toward the wrong goal.

Running multiple tracking setups often leads to inflated conversion data, which confuses Google’s bidding algorithm.

As Google pushes broad match harder, accounts without strong negative keyword lists are losing money on irrelevant searches.

Google is becoming stricter. Poor landing page speed, mobile experience, or unclear offers are hurting ad rankings and ROAS.

Running only one or two ad angles limits reach and performance. In 2026, successful accounts test multiple angles, offers, and creative formats.

Many advertisers try to fix performance by spending more instead of fixing foundational issues first.

What You Should Do Right Now

Google’s algorithm and bidding systems have become more sophisticated. Small tracking or strategy errors now have a bigger impact on performance than they did a few years ago.

With the rise of AI Max, Demand Gen, and AI Mode, Google is placing more weight on data quality, user experience, and creative relevance. Accounts that don’t fix basic mistakes are falling further behind.

6 Common Google Ads Mistakes (And How to Fix Them)

1. Using the Wrong Primary Conversion Action

Many e-commerce accounts set both “Add to Cart” and “Purchase” as primary conversions. Google then optimizes toward whatever action happens more frequently — which is almost always Add to Cart.

Fix: Make only “Purchase” (or your most valuable conversion) the primary action. Set Add to Cart and other micro-conversions as secondary.

2. Duplicate Conversion Tracking

This is very common on Shopify stores. Running both the native Google & YouTube app integration and a separate Google Tag often causes conversions to fire twice.

Fix: Audit your conversion actions. Compare Google’s reported conversions with your actual store orders. Remove duplicate setups.

3. Weak or Missing Negative Keyword Strategy

As Google continues to push broad match, accounts without strong negative keyword lists waste budget on irrelevant searches.

Fix: Regularly review search terms and build robust negative keyword lists at the campaign and account level.

4. Ignoring Landing Page Experience

Google is increasingly factoring in what happens after the click. Slow load times, poor mobile experience, or unclear offers can hurt ad performance.

Fix: Improve page speed, mobile responsiveness, and offer clarity. Test landing pages the same way you test ads.

5. Not Testing Enough Creative Angles

Many accounts run only one or two ad angles and wonder why results are flat. In 2026, winning accounts test multiple angles, offers, and creative formats.

Fix: Build a testing system. Run different hooks, offers, and creative styles consistently instead of relying on one winning ad.

6. Trying to Fix Performance by Increasing Budget

This is one of the most common reactions when performance drops. However, increasing budget on a broken foundation usually just burns more money.

Fix: Before increasing budget, audit tracking, negative keywords, creative testing, and landing page experience.

Google Ads Best Practices Checklist for 2026

Use this checklist to audit your accounts:

  • Only your most valuable conversion is set as primary
  • No duplicate conversion tracking is firing
  • Strong negative keyword lists are in place
  • Landing pages are fast, mobile-friendly, and clear
  • You are actively testing multiple creative angles and offers
  • You have a process for reviewing search terms regularly
  • First-party data and Consent Mode are properly implemented
  • You are testing AI Max alongside traditional campaigns

Why These Mistakes Matter More in 2026

  1. Audit your conversion actions — Make sure only your best conversion is primary.

  2. Check for duplicate tracking — Compare Google data with actual orders.

  3. Build or improve your negative keyword lists.

  4. Review your top campaigns using the checklist above.

  5. Start a structured creative testing process if you don’t already have one.

Frequently Asked Questions

Quick answers to the most common questions about Google Ads.

What is the most common Google Ads mistake in 2026?

Using the wrong primary conversion action and having duplicate tracking are currently two of the most frequent issues we see.

Not necessarily. You can often fix tracking and negative keywords without pausing campaigns. Just monitor performance closely after changes.

At minimum once per week for active campaigns. High-spend accounts should review more frequently.

It’s better to fix the foundation first, then test AI Max. Otherwise, you risk feeding the algorithm bad data.

Final Thoughts

Most Google Ads performance issues in 2026 aren’t caused by a lack of budget — they’re caused by foundational mistakes in tracking, strategy, and testing.

The accounts that consistently perform well are the ones that treat Google Ads like a system: clean data, strong negative keywords, continuous creative testing, and good landing page experience.

If you fix these common mistakes before trying to scale, you’ll usually see better results with less wasted spend.

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