Two pieces of published research do most of the work in this area. They are frequently blended together and misquoted online, so both are set out separately here with the figures each one actually reported.
Harvard Business Review, 2011, response times in practice
Oldroyd, McElheran and Elkington audited 2,241 US companies by submitting test web enquiries and measuring how long each took to respond. The findings:
- Average first response time was 42 hours, among firms that responded at all.
- 23% never responded to the enquiry.
- Firms responding within an hour were roughly seven times more likely to have a meaningful conversation with a decision-maker than those responding in the second hour.
Source: “The Short Life of Online Sales Leads”, Harvard Business Review, March 2011.
MIT Sloan / InsideSales, the five-minute threshold
A separate study led by Dr James Oldroyd analysed three years of data across six companies, covering more than 15,000 leads and over 100,000 call attempts. It measured how the odds changed with response delay:
- The odds of qualifying a lead were about 21 times greater when contact was attempted at 5 minutes rather than 30 minutes.
- The odds of making contact at all were about 100 times greater at 5 minutes than at 30 minutes.
What these studies do not show
Both measured web-form enquiries, not inbound phone calls. There is no equivalent peer-reviewed research on missed calls to Australian trades and service businesses. Figures circulating online about missed-call costs generally trace back to vendor surveys rather than published studies, which is why they are not quoted here.
The reasonable inference, not a measured finding, is that the phone is likely worse than the web-form data suggests: a caller has an alternative one tap away, and an unanswered call leaves no record for you to follow up.
What it means in practice
The practical threshold that emerges is minutes, not hours. For most operators a consistent five-minute response is not achievable manually, which is the gap AI phone answering and missed-call text-back are built to close.
To put your own numbers against it, use the lead leak calculator or read the worked example on the cost of a missed call.
Note: This page is part of Clearline AI's research library. Where specific statistics are cited, the primary source is linked. Where a figure is an estimate, a modelled scenario, or industry-reported rather than peer-reviewed, that is stated explicitly.