Most multi-service SMBs (a contractor that does kitchens + bathrooms + additions, a clinic that does dental + cosmetic + ortho, a firm with three practice areas) struggle to allocate Google Ads budget across the service lines. Spread evenly, every campaign is starved; concentrated wrong, the high-margin services are starved while the low-margin ones bleed budget. (If you’re upstream of this and still picking between PPC and SEO as your anchor, read PPC vs SEO first. For the full Google Ads playbook, the complete guide is here.)
The framework
- Calculate revenue contribution per service line over the last 12 months.
- Calculate gross margin per service line. Not revenue — margin.
- Calculate cost per acquisition target per service line based on margin (a $40k project can absorb a $400 CPA; a $400 service cannot).
- Allocate budget initially in proportion to margin contribution, not revenue.
The structural setup
One campaign per service line. Distinct ad groups within each. Distinct landing pages. Distinct conversion tracking — wire the GA4 conversion events per service line, not one mega-event. The most common SMB mistake is one mega-campaign with everything in it — which makes it impossible to know which service is performing and which is bleeding.
The 90-day rebalance cadence
Every 90 days, rebalance. Service lines that are hitting CPA targets get more budget; service lines that aren’t get reduced or paused for a structural fix (better landing page, better keywords, better creative). The rebalance is not optional — the markets shift, the seasonal patterns shift, the competitive set shifts.
