You paid for the ad. You paid for the SEO piece. You paid for the trade-show pull-through. The visitor arrived. Then they left, silent. That silence has a price tag, and it’s smaller than you fear but bigger than you think. Let’s do the math on a napkin.
The napkin formula
Three numbers. Your monthly website visits. Your average deal size. Your current conversion from visitor to customer. Multiply, divide, done. Everyone can do this in ten minutes without a spreadsheet.
Plain word
‘Conversion rate’ just means: out of 100 visitors, how many end up buying something. For most B2B sites that’s 1 in 200 — call it 0.5%.
A worked example
Say you get 4,000 website visits a month. Your average B2B deal is €5,000. Historical conversion visitor→customer is 0.4%. That means 16 customers a month, or €80,000 in monthly deals attributed to the site.
On average, each visit is worth: €80,000 ÷ 4,000 = €20. Every single visitor. Yes, the vast majority are worth nothing individually and a few are worth thousands — that’s how averages work. But if you leak 500 visits a month because your site is slow, that’s €10,000 of monthly deal-flow disappearing into the browser back button.
Do it for your own site
| Line | Your number | How to get it |
|---|---|---|
| A. Monthly website visits | ___ | Google Analytics |
| B. Average deal size (€) | ___ | Sales/CRM |
| C. Conversion rate visitor→customer (%) | ___ | Deals ÷ Visits × 100 |
| D. Monthly revenue from site (B × A × C ÷ 100) | ___ | |
| E. Value per visit (D ÷ A) | ___ | |
| F. Value of 100 lost visits (E × 100) | ___ |
The uncomfortable multiplier
The number in row F is not just today’s loss. It’s the recurring cost every month the leak stays open. A €2,000 monthly leak is a €24,000 annual line item nobody is looking at, because it never shows up as a bill.
What you can actually recover
You will not save every lost visitor. Most were browsing on a phone at 22:00 out of curiosity. What you can do:
- See the company behind the ones from businesses — most of them stay hidden today.
- Reach out to the ones who visited a real intent page (pricing, ‘how it works’, product).
- Fix the top-3 pages people bounce from — small wins here compound.
A realistic ambition for a small B2B site is recovering somewhere in the low-single-digit-percent range as additional pipeline. On the worked example above, recovering 2% of otherwise-lost visits as identified companies would surface roughly 80 named businesses a month you would never otherwise know.
Why the owner should care, not just marketing
Because pipeline recovery has the same effect as an ad-budget increase, minus the ad budget. If a €199/month tool lets you see 80 extra companies and turn even one into a customer, the math finishes itself. This isn’t a promise — it’s a napkin. Do the napkin.
- Related: [The 97% gap: why most visitors stay anonymous](/blog/the-97-percent-gap-anonymous-website-visitors)
- Related: [Why your best leads never fill out forms](/blog/why-your-best-leads-never-fill-out-forms)
- Related: [The first 14 days with visitor identification](/blog/first-14-days-with-visitor-identification-realistic-diary)
Published by
lead.box Team
More articles
See lead.box on your own traffic
Start free — no card, no sales call required. Or book a 20-minute walk-through if you want the guided tour.