Stop Asking How Much to Spend on Marketing

You’re sitting at your desk, staring at a profit and loss statement, trying to figure out if you should spend $5,000 or $8,000 on marketing this month. Someone told you 10% of revenue is the magic number.

Here’s the problem: the guy down the street who’s pulling more jobs than you isn’t asking what percentage to spend. He’s asking how much he can afford to spend to acquire a customer, and then spending exactly that much.

You’re playing the wrong game.

The 7-10% Rule Is a Trap - Here’s What Actually Works

The 7-10% rule for HVAC marketing budgets sounds clean. It’s easy to calculate. And it’s completely disconnected from whether you’re trying to grow, hold steady, or survive.

A company doing $500K in revenue spending 7% is at $35K a year. A company doing $2M spending the same percentage is at $140K. Same percentage, wildly different outcomes, because the $500K company needs to grow and the $2M company might just need to defend.

The real benchmark isn’t a percentage of revenue. It’s what happens when you spend it. Companies that spend 10-15% tend to grow 20-30% year over year. Companies that spend under 5% stagnate. But that’s a correlation, not a rule. If you’re spending 12% and getting 3% growth, the percentage wasn’t the problem.

The trap is treating the percentage as the answer instead of the starting question.

Your Cost Per Lead Is a Lie (Unless You Know Your ASPL)

I talked to an HVAC owner last month who was thrilled about his $80 cost per lead. He was getting 40 leads a month for $3,200. Sounded great.

Then I asked what his close rate was. 25%. And his average ticket? $400.

$80 CPL. $100 revenue per lead. He was losing money on every lead that didn’t book, and his margin on the ones that did was thin.

The average cost per paying customer in HVAC is $472. The average ticket value is $2,465. That’s a 5:1 ratio. That works.

But here’s where it gets ugly. Google Ads cost per lead ranges from $80 to $150. Blended average is $104. But branded search CPL is $34, and non-branded is $149. If you’re looking at a blended average, you don’t know which part of your funnel is working.

The metric that matters is Average Sale Per Lead (ASPL). Low CPL means nothing if your ASPL is also low. A $45 lead that books a $200 tune-up is worse than a $120 lead that books a $3,500 system replacement. Focusing on CPL alone is how you optimize your way into unprofitable growth.

The $8,300/Month Trap: Why Your Budget Needs a System, Not a Number

A contractor making $1M in revenue at 10% has $8,300 a month for marketing. That’s a solid number. It’s also meaningless if you don’t have a system.

I’ve seen owners take that $8,300 and spread it across Google Ads, Facebook, direct mail, SEO, and a billboard. Five channels, none of them getting enough budget to actually work. The recommendation is to go deep on 1-2 channels rather than spreading across five. But most owners do the opposite because they’re afraid of missing something.

A marketing budget without a system is just a donation to Google. You need to know which channel is feeding which part of your funnel, what each lead costs by source, and what your close rate is per channel.

I audited a company last year that was spending $4,000 a month on SEO and $3,000 on Google Ads. Their SEO was generating 15 calls a month at $266 per lead. Their Google Ads were generating 40 calls at $75 per lead. They were spending more on the channel that cost them 3.5x more per lead. When I asked why, the owner said “SEO is long-term.”

Long-term doesn’t mean unprofitable.

The Real Benchmark: CAC-to-CLV Ratio, Not Percentage of Revenue

Here’s the math that matters. Customer Acquisition Cost in HVAC runs $200-$600 per booked job. Customer Lifetime Value runs $1,200-$3,500. That’s a 3:1 to 6:1 ratio.

If your CAC is $472 and your CLV is $2,465, you can spend more than 10% of revenue on marketing and still be profitable. The percentage of revenue you spend doesn’t tell you if you’re efficient. The ratio tells you.

Most owners don’t know their CLV. They know their average ticket, but they don’t track how many times a customer comes back, what they spend on maintenance contracts, or how long they stay. Without that number, you’re guessing.

The net profit margin in HVAC is around 8%. That’s tight. If you’re spending 10% on marketing and your margin is 8%, you’re in the red before you pay your techs. Unless your CLV is high enough that the first job is a loss leader for the next five years of service.

That’s the calculation nobody does. They just pick a percentage.

The One Thing That’s Costing You More Than Any Ad Spend

Here’s the part that hurts. 30% of inbound calls go unanswered. Not missed. Not sent to voicemail. They ring until the caller gives up. That’s one in three people who wanted to give you money, and you let them hang up.

The average missed call in HVAC represents $350 in lost revenue. If you’re getting 50 calls a day and missing 15, that’s $5,250 a day walking out the door. $157,500 a month. You’re not losing money on marketing. You’re bleeding it through the phone.

And here’s the thing: you already paid for those calls. Every dollar you spent on Google Ads, SEO, or Local Services Ads was a bet that someone would call. When you don’t answer, you’re not just losing the sale. You’re burning the ad spend too.

The fix isn’t complicated. Answer within three rings. Call connection rate should hit 70-85%. If you’re below that, you’re not running a business. You’re running a donation center for Google.

What to Do Monday Morning

Pull last month’s invoice. Right now, while you’re reading this. Open it on your phone if you have to. Find every lead source, then divide your ad spend by jobs you actually invoiced, not leads, jobs. If your top source is a shared lead service charging $180 a click and converting at 3%, you’re not running marketing. You’re paying ransom.

Specifically: CallRail integrates with Google Ads and pulls call data automatically. BirdEye and Podium both connect to ServiceTitan and show you which channel produced which invoice. If you can’t name your true cost per booked job by tomorrow, your agency knows something you don’t, and they’re billing you for the gap.

Then calculate your CLV. The formula is simple: average purchase value × average purchases per year × average customer lifespan. If your average ticket is $400 and a customer comes back twice a year for five years, that’s $4,000. If your CAC is $472, you’re at 8.5:1. That’s healthy. But if your average ticket is $200 and they only come once, your CLV is $200 and you’re losing money on every customer you acquire.

The difference between a 3:1 and a 6:1 ratio isn’t luck. It’s knowing which customers to chase and which to fire.

The Bottom Line

Stop asking how much to spend. Start asking what you’re buying.

A marketing budget isn’t a percentage of revenue. It’s the price of a customer. If you don’t know that price, you can’t know if you’re getting a deal or getting robbed.

The guy down the street who’s pulling more jobs than you? He knows his numbers. He knows his CAC, his CLV, and his close rate per channel. He answers his phone within three rings. He cuts channels that don’t work within 90 days.

He’s not smarter than you. He just stopped asking the wrong question.

Now go pull that invoice.