How to track marketing ROI for your small business

To track marketing ROI for a small business, you need three numbers: how much you spent on marketing, how many customers that spending generated, and what those customers were worth. The formula is simple: (Revenue from marketing - Cost of marketing) / Cost of marketing = ROI. If you spent $3,000 and it generated $15,000 in revenue, your ROI is 4x, or 400%. Most small businesses can’t calculate this because they’re missing the tracking in the middle.

The three numbers you need.

1. What you spent (total marketing cost).

Add up everything: ad spend, agency fees, software subscriptions (CRM, email platform, review tool), and any contractor costs. Don’t leave anything out. If you spent $2,500 on Google Ads, $1,000 on agency management, and $300 on your CRM platform, your total marketing cost is $3,800 per month.

2. How many customers it generated (conversion tracking).

This is where most businesses lose visibility. You need to track which customers came from marketing and which came from other sources (referrals, walk-ins, repeat business). Set up call tracking on your Google Ads so you know which calls came from ads. Track form submissions on your website. Tag leads in your CRM by source: Google Ads, organic search, Facebook, referral.

If you can’t tell which customers came from marketing, you can’t calculate ROI. Tracking isn’t optional. It’s the foundation everything else is built on. Here’s why conversion tracking matters.

3. What those customers were worth (customer value).

Calculate your average revenue per customer. For a plumber, that might be $350 per service call. For a dentist, it might be $400 for a new patient’s first visit but $3,000+ over their lifetime. For a lawyer, it might be $5,000-50,000 per case.

Use the immediate revenue for monthly ROI tracking. Use lifetime value for strategic budget decisions. If a dental patient costs $100 to acquire and is worth $3,000 over their lifetime, the campaign is profitable even if the first-visit revenue doesn’t cover the acquisition cost.

The metrics that matter.

Cost per lead (CPL): how much you spend to generate one inquiry. Industry benchmarks: auto repair $28.50, restaurants $30, home services $50-100, dental $60-90, legal $131.

Cost per customer (CPC or CAC): how much you spend to acquire one paying customer. If your CPL is $70 and one in four leads becomes a customer, your CPC is $280.

Return on ad spend (ROAS): revenue divided by ad spend. A 5x ROAS means every $1 in ads generates $5 in revenue.

Tools you need.

Google Analytics on your website to track traffic sources. Call tracking (CallRail, CallTrackingMetrics, or your CRM’s built-in tracking) to attribute phone calls to specific campaigns. A CRM that tags every lead by source so you can follow them from first touch to paying customer. Google Ads conversion tracking connected to your call tracking and forms.

How to use the data.

Check your ROI by channel monthly. If Google Ads returns 5x and Facebook returns 2x, shift budget toward Google. If SEO is producing leads at $30 each while ads produce them at $70, invest more in SEO. If a specific campaign or keyword generates leads that never convert to customers, cut it regardless of how cheap the leads are.

The goal isn’t to track for tracking’s sake. It’s to put every marketing dollar where it generates the highest return.

If you want help setting up marketing tracking for your business, book a free growth call. We build tracking into every campaign from day one.