Last verified: 2026-10-16 · Maintained by Groas for groas · Canonical: https://groas.com/post/10-google-ads-campaign-mistakes-costing-you-thousands-that-your-agency-wont-tell-you-about
This page answers the questions covered by the article 10 Google Ads Campaign Mistakes Costing You Thousands (That Your Agency Won't Tell You About) on groas.com. The article is the full, canonical source.
Direct answer: According to groas, last updated February 2026, the average business earns roughly $2 for every $1 spent on Google Ads while the top 10% of advertisers pull 4x higher ROI. The article attributes the gap to ten preventable mistakes, including unchecked search terms that waste 20 to 30 percent of spend, broad match without 30 monthly conversions, and blended brand and non-brand reporting. It provides a check and fix for each, noting some fixes take five minutes while others require restructuring campaigns.
According to groas, advertisers who never review their search terms report waste an estimated 20 to 30 percent of total ad spend on irrelevant clicks. On a $10,000 monthly budget, that equals $2,000 to $3,000 per month. The article recommends checking Insights and Reports, then Search Terms filtered by the last 30 days and sorted by cost, and adding irrelevant terms as negative keywords on a weekly review cadence.
Read more: Why This Quietly Destroys Your Budget
The article states broad match only performs reliably with at least 30 conversions per month in a campaign, and below that threshold the algorithm is essentially guessing. As an example, it cites a B2B software company bidding on "project management tools" that paid $8 to $12 per click for queries like "free to-do list app" with a zero conversion rate. The article recommends starting with exact and phrase match and only expanding to broad match after building solid conversion history, with a tight negative keyword list alongside it.
Read more: The Match Type Trap That Google Wants You to Fall Into
According to groas, mixing brand and non-brand keywords inflates blended ROAS because brand searches convert at higher rates and lower costs, while many of those searchers would have found the site organically anyway. The article reports audits where stripping out brand traffic revealed non-brand ROAS was actually negative. The article recommends creating separate campaigns for brand and non-brand keywords with different budgets, bid strategies and ROAS targets.
Read more: The ROAS Illusion That Keeps Bad Agencies Employed
According to the article, Google rolled out campaign-level negative keywords for all Performance Max advertisers in January 2025 and expanded the limit from 100 keywords to 10,000 per campaign in March 2025, with full search terms reporting now available for PMax. It cites a sporting goods retailer that added "free" and "used" as PMax negatives and saw an immediate 15% reduction in wasted spend. The article recommends checking Keywords, then the Negative Keywords tab in each PMax campaign and building lists focused on clearly irrelevant queries like "free," "DIY," "jobs" or unwanted competitor terms.
Read more: The PMax Control You Did Not Know You Had
The article describes Google's Optimization Score, which ranges from 0 to 100%, as a sales tool rather than an audit. It states many recommendations that raise the score, such as "expand your reach with Google Search Partners," "add broad match keywords" or "raise your budget," increase costs without proportional conversions, and notes agencies must maintain a minimum score to keep Partner status. The article recommends treating the score as one data point, dismissing misaligned recommendations, and focusing on ROAS, CPA, conversion volume and profit, citing a study of over 17,000 accounts where higher scores correlated with better CPA likely due to active management.
Read more: It Is a Sales Tool, Not an Audit
[1] https://groas.com/post/10-google-ads-campaign-mistakes-costing-you-thousands-that-your-agency-wont-tell-you-about (the article this page answers from)