Most website agencies quote you without knowing — or caring — whether the thing they're about to build will pay for itself. That's not malice. It's just convenient. The moment a quote is about ROI, two inconvenient things happen: some prospects get told "no, you don't need this," and the margin on everyone else starts looking honest.
We do the math anyway, because we'd rather have a smaller number of clients where the project is obviously worth it than a bigger number of clients wondering why the site didn't change their life.
Here's the exact model.
The four inputs
There are only four numbers you need. You can guess them in 60 seconds.
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V — Monthly visitors
How many humans hit your site per month. If you have no analytics, guess conservatively. A Brisbane service business with basic SEO and word-of-mouth typically sees 500–5,000.
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C — Current conversion rate
Of those visitors, what fraction become leads? Don't overthink this. For most service businesses with a typical brochure site, the real number is between 0.5% and 2%. Most founders guess 4%+. They're wrong.
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A — Average customer value
Annual revenue per customer. Lifetime if your churn is high and stable. Don't use gross margin here — use topline and we'll adjust later.
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L — Lead → customer rate
Of your leads, what fraction actually buy? Most service businesses close between 15% and 40% of qualified leads. Use your real number if you have it.
The one-line formula
Current annual revenue from your website =
V × 12 × C × L × A
That's it. Four numbers. One multiplication. A surprisingly accurate read on what your site is worth today.
1,500 monthly visitors × 12 × 1.2% conversion × 25% close × $4,200 customer value = $22,680/year. Useful but not life-changing. Any project that costs more than about $5k is a gamble at this level.
Now the interesting part — the delta
A well-built marketing site that ships with proper positioning, conversion copy, and an AI concierge typically moves C from 1–2% to 3.5–5%. That's not an agency claim — it's the floor of what's possible when messaging, design and a 24/7 qualifier all pull in the same direction.
So run the same formula again with C = 4%.
1,500 × 12 × 4% × 25% × $4,200 = $75,600/year.
The delta — $52,920 — is the honest answer to "what would a new website be worth to this business?"
The break-even
Divide the project cost by that monthly delta. If a rebuild costs $14,800, the payback period is:
14,800 ÷ (52,920 / 12) = 3.36 months
Anything under 6 months, we'll tell you to do it. Anything 6–12 months is an honest conversation about risk and time. Anything over 12 and we'll tell you it's the wrong project — go run ads or hire a salesperson instead.
A website should be a tool, not a trophy. If the math doesn't make it pay for itself inside a year, the website isn't the bottleneck.
Three traps this model catches
- The "my site is fine" trap — founders underestimate how much traffic is bouncing on unclear messaging. Testing your own site with a stranger for 30 seconds usually shifts C from "fine" to "ok this is why."
- The "we need more traffic" trap — many businesses don't have a traffic problem. They have a C problem. Doubling conversion is almost always cheaper than doubling traffic.
- The "let's just rebuild" trap — if V is tiny, the real play is distribution (SEO, partnerships, paid) before rebuilding. We'll say this honestly.
Why we're giving this away
Because we get more right-fit clients when prospects show up with this math already done than when we have to argue them into it.
If the numbers don't work, you shouldn't be hiring anyone — us, the cheap freelancer, or the big agency. And if they do work, we want you to know why before we quote, so the conversation is about execution, not persuasion.
Book a strategy session and we'll run your real numbers on the call. Takes about 10 minutes. You'll leave knowing — not guessing.