How do you calculate response-time SLA for inbound and prove it's driving conversion?
Brief
Every 5-minute delay in first touch costs 1–2% of conversion rate. Lock SLA at 4 hours max.
Detail
Response speed is a direct converter. The math is unambiguous:
- Contacted within 5 minutes: 37% conversion (InsideSales / HubSpot 2023 data)
- Contacted within 1 hour: 7–9% conversion
- Contacted within 24 hours: <1% conversion
- Contacted after 48 hours: Near-zero recovery
The cliff is real. Most inbound teams ignore it and wonder why SQL conversion tanks.
SLA Framework
Tier 1 (Hot leads, high-fit): 15-minute response Tier 2 (Medium-fit): 1-hour response Tier 3 (Warm, nurture-track): 4-hour response Tier 4 (Content-only, no sales call): 24-hour auto-nurture
Proving the Lift
Track three cohorts over 30 days:
| Response Window | MQL Count | SQL Conversion | Deal Rate |
|---|---|---|---|
| <15 min | 124 | 38% | 28% |
| 15–60 min | 118 | 22% | 18% |
| 1–4 hours | 131 | 14% | 9% |
| >4 hours | 87 | 4% | 1% |
Calculate marginal value: If 100 leads per month currently respond in 2+ hours but move to 1 hour, you gain +1,800 MQL-to-SQL dollars in monthly pipeline (assuming 30% conversion lift × 100 MQLs × $50K ACV = $1.5M annual impact).
Most teams lack the routing infra. Fix that first; SLA discipline second.
TAGS: response-time,SLA,inbound-conversion,first-touch,routing,lead-velocity