How We Increased Conversions by 52% While Staying Within Target CPA for a Criminal Defence Law Firm
The Challenge
- SituationA criminal defence law firm was running a modest Google Ads operation generating 974 conversions over nearly two years, primarily through two traditional search campaigns targeting exact and phrase match keywords.
- ProblemThe account was underperforming its potential, with ROAS sitting at just 0.83x and limited campaign diversification. The firm had no brand protection, no competitor targeting, and wasn't leveraging newer Google Ads formats like Performance Max or call-only ads—missing critical opportunities to capture high-intent prospects at different stages of the decision journey.
- StakesIn criminal defence, every missed enquiry represents someone who needed legal representation but went elsewhere. The firm needed to scale lead generation while maintaining cost efficiency, with a hard ceiling of £50 CPA to ensure profitability.
The Results
| Metric | Before | After | Change |
|---|---|---|---|
| Conversions | 974 | 1,478 | +52% |
| CPA | £36.35 | £42.51 | +17% |
| Conversion Value | £29,396 | £54,049 | +84% |
| ROAS | 0.83x | 0.86x | +4% |
| Monthly Spend | £1,562 | £2,856 | +83% |
| Impressions | 189,245 | 559,542 | +196% |
The Approach
We implemented a multi-pronged expansion strategy focused on diversifying traffic sources and capturing demand across the entire decision funnel, while closely monitoring CPA to stay within the £50 threshold.
Launched a Performance Max campaign to leverage Google's automation and reach prospects across Search, Display, YouTube, and Discover—contributing 192 new conversions
Introduced competitor targeting campaigns (both standard and call-only formats) to capture prospects actively researching alternative firms, generating 183 additional conversions at a strong 1.16x ROAS
Deployed dedicated call-only ad campaigns to prioritise immediate phone enquiries, scaling from just 3 conversions to 93—a 3,003% increase
Implemented brand protection campaigns to defend against competitor bidding and capture high-intent branded searches at an exceptional 3.90x ROAS
Rebalanced budget allocation, reducing spend on the underperforming exact match campaign while scaling the phrase/broad campaign that demonstrated stronger volume potential
Delivered 504 additional client enquiries while maintaining CPA at £42.51—within the £50 target threshold
By diversifying beyond the original two-campaign structure, we nearly tripled impression volume and drove 504 additional client enquiries—all while keeping CPA well within the £50 target at £42.51. The competitor and call-only campaigns proved particularly effective, with competitor targeting achieving a 1.16x ROAS and call-only ads scaling from virtually zero to 93 conversions. Conversion value increased by 84%, demonstrating that the additional volume didn't sacrifice lead quality.
Campaign diversification across match types, formats, and intent signals unlocked significant scale without compromising efficiency—don't rely on a single traffic source
Competitor targeting can be highly profitable in professional services, capturing prospects actively in-market and comparing options
Call-only campaigns deserve dedicated budget in industries where phone enquiries convert at higher rates than form fills
Strategic CPA increases can be acceptable when the absolute volume and total conversion value justify the investment—£42.51 CPA delivering 1,478 conversions outperforms £36.35 CPA delivering only 974