You Should Know These Numbers as Well as Your Close Rate
Most business owners can tell you their average deal size and roughly how many jobs they completed last month. Far fewer can tell you their cost per lead by channel, their cost per qualified lead, or their actual return on ad spend. This creates a dynamic where the agency knows exactly how the marketing is performing but the business owner is relying on monthly reports they may or may not fully understand.
You do not need a marketing degree to read an ad dashboard. You need to understand five numbers, what each one means for your business, and what the benchmarks look like so you can have an informed conversation with whoever is managing your campaigns.
The Five Numbers That Matter
Cost per lead (CPL). Total ad spend divided by total leads generated. If you spent R5,000 on Google Ads last month and got 80 leads, your CPL is R62.50. In 2026, a reasonable CPL on Google Ads for service businesses is R35-75 depending on your market. If your CPL is consistently above R100, something in the campaign structure, targeting, or landing page needs attention.
Cost per qualified lead (CPQL). This is the number most agencies do not volunteer. Of those 80 leads, how many were actually qualified, meaning they are the decision-maker, the project is real, and the budget fits your pricing? If 40 of 80 leads were qualified, your CPQL is R125. This number tells you about lead quality, which matters more than raw volume. A campaign generating cheap leads that never convert is more expensive than one generating pricier leads that actually book appointments.
Conversion rate. The percentage of people who click your ad and then become a lead by filling out a form or calling. Industry average for landing pages is around 3-5%. Below 3% usually indicates a problem with the landing page itself, slow load time, unclear offer, too many form fields, or a disconnect between what the ad promised and what the page delivers. Above 5% means the landing page is doing its job well.
Cost per acquisition (CPA). The total marketing cost to sign one customer. This is the number that connects marketing spend to actual revenue. If you spent R5,000 on marketing and signed 3 customers, your CPA is R1,667. Whether that number is healthy depends entirely on your average deal size and margins. For a R15,000 average job with 25% margins, a R1,667 CPA leaves room. For a R5,000 job with 15% margins, that same CPA eats into profitability fast.
Return on ad spend (ROAS). Revenue generated divided by ad spend. If you spent R5,000 and the 3 customers you signed represent R45,000 in revenue, your ROAS is 9x. This is the ultimate measure of whether your advertising is working. A ROAS below 5x usually means something needs to change, whether that is the campaign targeting, the sales process, or both.
How to Use This With Your Agency
Ask your agency to provide these five numbers in every monthly report, with trend lines showing whether each one is improving or declining over the past 90 days. If they push back on sharing cost per qualified lead or try to redirect the conversation to impressions and clicks, that tells you something important about how confident they are in the quality of results they are delivering. The agencies worth working with welcome this level of scrutiny because their numbers support the relationship.