Illingworth says 3 in 4 first replies land in hour one
He argues a silent inbox at hour 24 points at the list, not the subject line.
Richard Illingworth says a campaign that has run a full day with zero replies has already told you what is wrong, and it is not the subject line. He points to a breakdown by the founder of SmartLead covering six and a half thousand campaigns, which he says shows three out of four first replies landing inside the first hour of launch and 95% landing inside 72 hours.
His read on that is simple. If the inbox is clean and it goes quiet for a day, stop rewriting copy and go look at who you are actually sending to.
What the number is and is not
The data is not Illingworth's own sending. He is citing someone else's aggregate, and the post does not break out what counted as a reply, which verticals the campaigns covered, or over what period the six and a half thousand campaigns ran. Treat it as a rule of thumb about reply timing rather than a benchmark you can hold your own numbers against.
silence by hour 24 is a PROBLEM.
three out of four first replies land inside the FIRST hour of launch.
What it does give you is a cutoff. Most senders already know replies cluster early. The claim here is that the cluster is tighter than most people act like it is, which is what makes a 24 hour window usable as a signal rather than something you wait out.
The diagnostic
The practical move Illingworth describes is a fork. Silence at hour 24 on a campaign where deliverability is not in question sends you to the list, not the copy. That matches the position he has taken repeatedly, including his argument that a multi source build beats an Apollo-only pull by 3 to 4x.
The obvious catch is in the words "clean inbox". If you cannot confirm placement, silence tells you nothing at all, because an inbox that is quiet because nothing arrived looks exactly like an inbox that is quiet because the wrong people received a good email. Illingworth's own framing assumes you have already ruled that out. Most senders have not.
For people sending, the useful part is the speed, not the percentage. If first replies really do arrive that fast, you do not need a week to kill a campaign, and the time you currently spend rewriting subject lines on a dead send is time you could spend rebuilding the segment. The 24 hour mark is a prompt to go look, not proof the list is broken.
Know what is landing before you burn another domain
One email a day. Under three minutes. What the operators found out yesterday.