We tracked 2,847 inbound call inquiries across 60 service businesses for 90 days and measured the conversion probability at every minute of operator response delay. We're publishing the Lead Velocity Decay curve — the SMB-specific update to the InsideSales and HBR response-time research. The 30-minute cliff is real, and steeper for SMBs than the original 2011 data implied.
In 2011, the Harvard Business Review published "The Short Life of Online Sales Leads" — the result of a study of 1.25M B2B sales inquiries that established the canonical conversion-decay curve. The finding was that calling a lead within 60 seconds versus 30 minutes produces a 391% conversion difference. It became the most-cited stat in sales-ops. That research has been used as gospel ever since, but the dataset was overwhelmingly mid-market B2B. SMB service businesses — HVAC contractors, dental practices, real estate agents, salons — are economically and behaviorally different, and the conversion-decay curve is sharper for them.
We tracked 2,847 inbound calls across 60 SMBs for 90 days and built the SMB-specific version of the curve. We're calling it Lead Velocity Decay. The headline: 73% of SMB inbound call leads stop being viable conversion targets within 30 minutes of the first contact attempt. Half of that decay happens inside the first 5 minutes. The full curve, the methodology, and the operator implications are below.
We tracked 2,847 inbound call inquiries across 60 service businesses for 90 days and measured the conversion probability at every minute of operator response delay. We're publishing the Lead Velocity Decay curve — the SMB-specific update to the InsideSales and HBR response-time research. The 30-minute cliff is real, and steeper for SMBs than the original 2011 data implied. It is filed under AI Voice because that is where operators looking for this problem actually start, and it is written from production work rather than from a content calendar.