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How fast should you respond to a new lead? The research supports a plain answer: try to reply within the hour, and never let an inquiry go unanswered. The stricter rules you see quoted everywhere, five minutes or the customer is gone, rest on thinner ground than the blogs suggest. We opened the original sources on 10 November 2026. Two studies hold up, within limits their own authors state. A third famous number, that 78% of customers buy from whoever responds first, has no study behind it that we could find. Here is what each one measured, what none of them can tell you, and a target a busy team can actually keep.
The four numbers, and where they come from
| The claim | Where it comes from | What it measured |
|---|---|---|
| Nearly seven times more likely to qualify a lead if you try within an hour | Harvard Business Review, March 2011: 1.25 million leads at 42 US companies | A first contact attempt within an hour, against one made an hour later |
| 23% of companies never reply | The same article: an audit of 2,241 US companies | How long each took to answer one test inquiry from the web |
| 100 times and 21 times: five minutes against thirty | A 2007 study by InsideSales.com with James Oldroyd: six companies | Phone calls to web leads: the odds of reaching and of qualifying them |
| 78% buy from the first company to respond | A 2008 vendor white paper quoting one person | No sample or method given |
The Harvard Business Review article: the solid one
In March 2011 James Oldroyd, Kristina McElheran and David Elkington published The Short Life of Online Sales Leads. It reports two separate pieces of research, and they are often blended into one.
The audit. The authors audited 2,241 US companies, timing how long each took to respond to a test lead generated on the web. This is what came back:
- 37% responded within an hour.
- 16% responded within one to 24 hours.
- 24% took more than 24 hours.
- 23% never responded at all.
Among the companies that answered within 30 days, the average response time was 42 hours.
The lead study. A separate dataset covered 1.25 million sales leads received by 29 consumer and 13 business-to-business companies in the United States. Firms that tried to contact a lead within an hour were nearly seven times as likely to qualify it as firms that tried even an hour later, and more than 60 times as likely as firms that waited 24 hours or longer. The article defines qualifying as having a meaningful conversation with a key decision maker.
Two details matter when you quote it. The clock measures the first attempt, not a completed conversation. And the result is qualification, not a sale. It is also worth knowing who wrote it: Elkington was chairman and chief executive of InsideSales.com, a company that sells lead-response software. That doesn't make the data wrong. It does mean the best-known evidence for speed comes from people with a product in the field.
The five-minute rule: real data, narrower than its fame
The five-minute figure is older. On 16 October 2007, Elkington and Oldroyd presented the Lead Response Management study at a MarketingSherpa summit. The study's original web address is now for sale, but a copy of its overview page, printed in July 2008, is still online. It is often called "the MIT study" because Oldroyd was a faculty fellow at MIT at the time. The data came from the InsideSales.com system.
It examined three years of records from six companies: more than 15,000 web leads and more than 100,000 call attempts. Its headline findings:
- The odds of contacting a lead dropped 100 times when the first call came after 30 minutes instead of 5.
- The odds of qualifying a lead dropped 21 times over the same gap.
- Even between 5 and 10 minutes, contact odds fell 5 times and qualification odds 4 times.
Read the definitions before repeating these. A contact was a phone call that connected with a live person. Qualifying meant the lead was willing to enter the sales process, in some cases by setting an appointment, and each of the six companies recorded that in its own way. The overview also says, in so many words: "This study did not address close ratios."
So the popular version, that you are 21 times more likely to win the sale within five minutes, is not what the study found. It found that someone who has just filled in a web form picks up the phone, and that the effect fades within minutes. The examples in the overview are mortgage and insurance leads, sold to several competing firms at once. That is a real market, and for most service businesses it is not theirs.
The vendor itself was more careful than the people who quote it. In a post dated 6 November 2009, InsideSales asked whether a call within minutes is welcome when someone has only downloaded a white paper. Its answer was that it didn't know, and that as far as it was aware nobody did. It also left open whether an immediate response helps or hurts the sale itself.
The 78% claim: no study that we could find
You will see it on hundreds of pages: 78% of customers buy from the company that responds first. Neither study above contains it. The oldest version we could open is a white paper called First to Call from Leads360, a lead-management software company, in a copy saved by the Internet Archive in February 2009. Its summary says that in some industries 78% of buyers close with the company that contacted them first. Page 4 shows where that comes from: a remark attributed to one person at a firm called LeadQual, about buyers choosing a real estate agent. There is no sample, no method and no date.
Many later pages credit the figure to "Lead Connect". A 2021 vendor infographic we opened gives that name in brackets, with no title, year or link, and the leadconnect.com address redirected to a domain marketplace when we checked. If a study exists, nobody who cites it points to it. We would leave the number out of any business case.
What these studies cannot tell you
- They compare, they don't experiment. Companies that answer fast may also have better staff, better offers or hotter leads. The studies show that speed and success go together, not that one causes the other.
- They stop at qualification. Neither measured closed sales or income.
- They are American, and old. The call data predates October 2007 and the audit predates March 2011. Buyers now expect different things from email, chat and phone.
- They are mostly about phoning. The five-minute effect is about catching someone at their desk. An emailed reply has no such moment.
- They say nothing about quality. A fast reply with a wrong name or a promise you can't keep is worse than a good one an hour later.
What does hold up: two datasets point the same way. Attempts within the hour reach and qualify far more people, most companies are slower than that, and nearly a quarter never answer. For most businesses the cheapest gain is not a five-minute sprint. It is making sure no inquiry is missed, and answering the same day.
A target a busy team can keep
If you run the business and also do the work, nobody is watching the inbox every five minutes. Set three levels instead of one rule:
- The floor: every inquiry gets an answer. The audit's 23% is the number to beat first.
- The standard: within one working hour. For anything that arrives in opening hours. Evening and weekend inquiries get the first reply of the next working day.
- The stretch: within minutes, by phone. Only for clear buying signals, such as a request for a quote or a call back, and only if phoning suits your customers.
Then measure where you stand. Take your last 20 inquiries, note when each arrived and when your first personal reply went out, and count the ones that got none. The middle value of the rest is your median response time. It takes a quarter of an hour, and it is usually a surprise.
The HBR authors list reasons companies are slow: leads fetched from a system once a day instead of continuously, salespeople busy with their own prospecting, and rules for sharing leads out by region or fairness. In an owner-led business the causes are simpler. The inquiry is buried among other mail, and a good first reply takes thought you don't have between two appointments.
How a drafting assistant helps, without sending anything
Both causes can be reduced without hiring. In our test build, an automation checked the inbox every 2 minutes, labelled each new inquiry, copied its details into a lead sheet and left a reply in Drafts, inside the lead's own thread. On 50 test emails the sorting step recognised all 14 leads. The one draft we checked word by word ran to 93 words and asked two qualifying questions. A second automation drafted a follow-up when a lead had been quiet for three days, and stopped after the second.
That last rule is our judgement, not a research finding. The 2007 overview does say that after 20 hours every extra dial hurt the odds of contact, but that concerns repeated phone calls, not a polite email three days later. We know of no comparable study for email follow-ups.
What the assistant never does is send. A person reads each draft and presses the button, which is what makes the one-hour standard realistic: checking Drafts three times a day takes minutes when the writing is already done. If you are tempted to let it reply on its own to hit a faster number, read why an AI assistant should draft and never send first.
The whole build is in Your First AI Agent in a Weekend, inbox triage and lead follow-up edition, with every setting, the prompts and the test method. The first step, labelling Gmail automatically with AI in Zapier, is free to read here, and so are the results from our 50 test emails.
The honest summary is shorter than the slogans. Speed matters, the hour is the threshold the best evidence supports, and silence is the most expensive reply of all. Start by measuring your own median, fix the inquiries that never get answered, and let software do the sorting and the first draft while a person stays on the send button.
Frequently asked questions
How fast should you respond to a new lead? Within the hour if you can. A Harvard Business Review article from March 2011 reported that firms which tried to contact a web lead within an hour were nearly seven times as likely to qualify it as firms that tried an hour later. Above all, answer every inquiry: in the same article, 23% of 2,241 audited companies never replied.
Where does the five-minute rule for leads come from? From a 2007 study presented by InsideSales.com and James Oldroyd, based on phone calls to web leads at six companies. It found the odds of reaching a lead were 100 times lower, and of qualifying it 21 times lower, when the first call came after 30 minutes instead of 5. The study states that it did not address close ratios.
Is it true that 78% of customers buy from the first company to respond? We could not find a study behind it. The oldest version we could open is a 2008 white paper from a lead-software vendor, which attributes the figure to one person speaking about real estate, with no sample or method. Later pages credit a source called Lead Connect without a title, a year or a link.
Does a faster reply mean more sales? The two best-known studies do not show that directly. They measured whether a lead was reached and qualified, not whether it bought, and they compared companies instead of running an experiment. Speed and reaching people clearly go together in the data. Whether a reply in five minutes wins more business than one in forty is not something these studies answer.
How do I measure my own lead response time? Take your last 20 inquiries. For each, note when it arrived and when your first personal reply went out. Count the ones that never got a reply, then take the middle value of the rest. That median, and the number never answered, tell you more than an average does.