Calculate required volume and buffer

Most companies set budget by copying last year's spend or splitting evenly across channels. No calculation, no volume targets, no buffer for underperformance.

You need to work backwards. Start with revenue target. Divide by average deal size to get deals needed. Then work through your funnel conversion rates: deals to opportunities, opportunities to MQLs, MQLs to traffic. That's your required volume.

Add a 20% buffer because conversion rates fluctuate. Set maximum CAC per segment based on LTV. Now you know exactly how much traffic you need and what you can afford to pay for it.

This chapter shows you how to build that calculation for each segment, not just one averaged number for your entire business.

Start with your annual or quarterly revenue target. Divide by average deal size. That's total deals needed.

If you're targeting £500,000 in revenue and average deal size is £10,000, you need 50 deals. Simple maths, but most companies stop here.

Break it down by segment. Not all segments have the same deal size or close rate. Compliance-driven cybersecurity buyers might have smaller contracts (single department) than proactive CSOs (company-wide rollout).

Review last 12 months of closed deals. Segment by the belief-based segments you created in playbook 1. Calculate average deal size per segment.

Compliance-driven: £8,000 averageBreach-reactive: £15,000 average (urgency drives bigger scope)Proactive: £12,000 average

Now allocate your revenue target across segments based on where you see growth opportunity. Don't just average it. If breach-reactive converts fastest, weight more revenue there.

Target allocation example:

• Compliance-driven: £150,000 (19 deals at £8,000)
• Breach-reactive: £200,000 (13 deals at £15,000)
• Proactive: £150,000 (13 deals at £12,000)

You now have deals needed per segment, not one averaged target.

Pull your actual conversion rates from HubSpot or your CRM. You need rates for each stage: opportunity to deal, MQL to opportunity, traffic to MQL.

Don't use industry benchmarks. Use your real data from the last 6 to 12 months. Segment it by the belief-based segments if possible. If you don't have enough data per segment yet, use overall rates but track separately going forward.

Example conversion rates:

• Opportunity to deal: 25%
• MQL to opportunity: 40%
• Traffic to MQL: 3%

Work backwards from deals needed.

Compliance-driven segment (19 deals needed):

• Opportunities needed: 19 ÷ 0.25 = 76 opportunities
• MQLs needed: 76 ÷ 0.40 = 190 MQLs
• Traffic needed: 190 ÷ 0.03 = 6,333 visitors

Breach-reactive segment (13 deals needed):

• Opportunities needed: 13 ÷ 0.25 = 52 opportunities
• MQLs needed: 52 ÷ 0.40 = 130 MQLs
• Traffic needed: 130 ÷ 0.03 = 4,333 visitors

Proactive segment (13 deals needed):

• Opportunities needed: 13 ÷ 0.25 = 52 opportunities
• MQLs needed: 52 ÷ 0.40 = 130 MQLs
• Traffic needed: 130 ÷ 0.03 = 4,333 visitors

Total traffic needed: 15,000 visitors across all segments.

This is your baseline. Now add buffer.

Conversion rates fluctuate. Campaigns underperform. Seasonality hits. Add 20% to your traffic target as buffer.

15,000 visitors + 20% = 18,000 visitors needed.

Now calculate maximum CAC (cost per acquisition) you can afford per segment. Use this formula: (Average deal value × gross margin) ÷ 3.

The ÷ 3 ensures you're not spending more than one third of gross profit on acquisition, leaving room for retention, expansion, and profit.

Compliance-driven segment:

• Average deal: £8,000
• Gross margin: 70% = £5,600
• Max CAC: £5,600 ÷ 3 = £1,867

Breach-reactive segment:

• Average deal: £15,000
• Gross margin: 70% = £10,500
• Max CAC: £10,500 ÷ 3 = £3,500

Proactive segment:

• Average deal: £12,000
• Gross margin: 70% = £8,400
• Max CAC: £8,400 ÷ 3 = £2,800

These are your spending ceilings per segment. Any campaign exceeding these CAC targets for 4+ weeks gets killed.

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Create a simple table showing segment, traffic needed, deals needed, and max CAC.

This table drives all budget allocation decisions in the next chapter. You know exactly how much traffic each segment needs and what you can afford to pay.

Update this quarterly as deal sizes and conversion rates change. If breach-reactive close rate improves from 25% to 30%, you need fewer opportunities and therefore less traffic. Recalculate and reallocate budget.

You now have volume targets and CAC limits per segment. Next chapter: map which campaigns within each channel can deliver that volume at that cost.

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