The famous 100x statistic is real, it is from 2007, and it is not from Harvard Business Review.
Two separate landmark studies get merged into one misquoted sentence. Both are worth reading properly.
Two studies underlie almost every speed-to-lead claim, and they are constantly conflated. The 2007 MIT/InsideSales study led by Dr. James Oldroyd found that contacting a lead within five minutes rather than thirty changed the odds of making contact by about 100 times and the odds of qualifying by about 21. Harvard Business Review's separate 2011 audit of 2,241 US companies found an average first-response time of 42 hours, with 23% never responding at all. Different studies, different years, different measurements, and the 100x figure is routinely credited to HBR, which did not produce it.
What did each study actually measure?
The MIT/InsideSales work measured the effect of response speed on outcomes, using dial records. The HBR audit measured what companies actually do, by submitting inquiries and timing the replies. One is about the payoff of speed; the other is about how rarely anyone achieves it.
Why the provenance matters: the 2007 study is nearly two decades old and describes B2B lead follow-up by outbound dialling, in an era before the messaging channels most businesses now use. It is a real finding about a real mechanism, and it is not a measurement of how a plumbing company should handle an inbound call in 2026.
Quoting it accurately is also self-protective. A business that repeats "100x, according to Harvard" in a sales conversation and gets challenged has lost more than the point.
| MIT / InsideSales (2007) | Harvard Business Review (2011) | |
|---|---|---|
| Led by | Dr. James Oldroyd | HBR research team |
| Method | Analysis of dials and outcomes across six companies | Audit: submitted inquiries to companies and timed responses |
| Scale | 15,000+ leads, 100,000+ dial attempts | 2,241 US companies audited |
| Headline | 5 vs 30 minutes: ~100x contact odds, ~21x qualification odds | 42-hour average first response; 23% never responded |
| Also found | - | Responding within an hour: ~7x more likely to qualify than waiting an hour longer |
The 100x and 21x figures belong to the first column. They are frequently attributed to the second.
Why does speed have such a large effect?
Because response time is competing against the other options the person is working through. Someone who has just made an inquiry is in a short window where they are actively deciding. After it closes, they have either chosen somebody or stopped thinking about it, and the same message arrives into a completely different state of mind.
This is why the curve is so steep at the start and so flat later. The difference between five minutes and thirty is enormous because it spans the decision window. The difference between six hours and twelve is comparatively small, because both are outside it.
It also reframes what "answering the phone" is worth. A call answered live is a response time of zero, the theoretical limit of every speed-to-lead strategy, achieved without any follow-up process at all. Everything else in this category is an attempt to recover from having missed that.
What do these studies not tell a small service business?
Almost everything about its own phone. Both studies looked at B2B lead handling, mostly in larger organisations, using outbound follow-up to inbound web inquiries. A landscaper's inbound call from a stranger in June is a different act on a different channel.
The direction of the finding almost certainly transfers: faster is better, and the advantage is largest early. The magnitudes should not be transferred. Repeating "21x more likely to qualify" about a phone call is borrowing precision from a study that measured something else.
The honest version is simpler and does not need a citation: someone who calls you is choosing between you and the next number on their list, and they are choosing now.
A call answered live is a response time of zero, the theoretical limit of every speed-to-lead strategy, reached without any follow-up process at all, which is why the cheapest lead-response improvement available to most businesses is answering the phone.
Every follow-up sequence in this category exists to recover from a call nobody picked up. Answering it is strictly cheaper.
Start free pilotWhat this page is careful about
Both studies are frequently misquoted, and this page tries not to add to it.
- Attribution. The 100x and 21x figures are MIT/InsideSales, 2007. The 42-hour average and the 23% non-response figure are HBR, 2011.
- Age. The primary study is from 2007. It is cited for its mechanism, not as a current benchmark.
- Transferability. Neither study measured inbound phone calls to small service businesses. The direction transfers; the magnitudes should not be assumed to.
Questions this raises
- Where does the '100x more likely to connect' statistic come from?
- The 2007 Lead Response Management study by Dr. James Oldroyd, conducted with InsideSales.com. It compared contacting a lead at five minutes versus thirty. It is not a Harvard Business Review finding, though it is often credited as one.
- What did the Harvard Business Review study find?
- Its 2011 audit of 2,241 US companies found an average first response time of 42 hours and that 23% never responded at all. It also found firms responding within an hour were around seven times likelier to qualify a lead than those waiting an hour longer.
- Are these findings still valid?
- The mechanism, that inquiries have a short decision window, is durable. The specific magnitudes are from 2007 and 2011, measured on B2B lead follow-up, and should be treated as historical rather than as today's benchmark.
- Do these studies apply to inbound phone calls?
- Not directly. Both measured follow-up to web inquiries, largely B2B. A live-answered call is a stronger case than either study covers, because the response time is zero.
- What is the practical takeaway?
- The largest available improvement in response time is answering calls when they arrive. Every follow-up sequence is a recovery mechanism for having failed to.
Sources
- Lead Response Management Study (Dr. James Oldroyd)MIT / InsideSales.com2007, consulted 2026-08-09
- The Short Life of Online Sales LeadsHarvard Business Review2011, consulted 2026-08-09
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