Untested assumption

Are webinar reminder emails dead?

The question is theirs, from a thread with 33 points and 56 comments. It got a lot of confident answers and no test, which is also the state of the published literature.

Short answer

No — and the more useful answer is that nobody has tested them. The best-evidenced reminder literature there is, randomised trials running to tens of thousands of participants, compares text messages, phone calls, automated voice calls and no reminder at all. Not one arm of it is email. So when attendance halves on a sequence you did not change, you do not have evidence that email died; you have four things moving underneath a constant and no instrument pointed at any of them.

40% → 15%
One B2B operator's monthly webinar over two months, with the email sequence unchanged. n=1, self-reported
Source: u/kerblamophobe, r/marketing, 2026-03-12
RR 0.99
Attendance after a text-message reminder versus a phone-call reminder — no detectable difference. 3 trials, 2,509 participants (95% CI 0.95–1.02)
Source: Cochrane Review, 2013
0
Arms in that trial literature that tested email. Every comparison in it is a text message, a phone call, an automated voice call, or nothing

“Webinar attendance is dropping hard. Are emails dead?”

That is the whole question, posted by a B2B software marketer in March 2026 with the numbers attached. It is the clearest statement of the problem anyone has written down, and it is worth reading in full before anybody sells you an answer to it:

“We run a monthly educational webinar for our B2B software. Last year, we were getting about 40 percent of registrants to actually show up live. The last two months, that number dropped to barely 15 percent. We have not changed our email sequence at all. We send a confirmation, a 24 hour reminder, and a 1 hour reminder. Are spam filters just eating our webinar links now? How are you guys getting registrants to actually log in?”
u/kerblamophobe, r/marketing, 2026-03-12[1] (33 points, 56 comments)

Fifty-six comments arrived. Not one of them tested the question, and the answer the thread upvoted highest was to send another email.

The top answer to “are emails dead” was: send an email

“Send an email survey to this who didn’t attend” took 67 points[2], more than any other reply. Second place, at 42 points each, went to a comms specialist asking whether the registrants were the same people every month[3], and to an attendee explaining that they skip webinars because everyone sends a recording now — the reason that has its own page. A fourth answer, at 14 points, was one sentence: “Phone them up and ask.”[4] Nobody in the thread proposed abandoning email, and nobody proposed a way to find out.

“Are spam filters just eating our webinar links now?”

Raised in the post itself, and never resolved. Across 56 comments exactly one person engaged with it directly[5], naming the deliverability checks worth running — whether the sending IP had recently been blacklisted, whether send volume had gone up, whether the email platform had been migrated, since a fresh IP has a higher chance of being marked as spam. Nobody reported having run any of them.

This matters more than the thread treated it, because it is the one hypothesis on the list that is cheap to eliminate, and eliminating it is what tells you whether you have a delivery problem or an interest problem. Those two problems have nothing in common and the fixes share no steps. What follows is not our method; it is the thread’s own suggestions, ordered by how many points each one carried.

1

Ask the people who did not attend (67 points)

The highest-voted answer in the thread: send a survey to the no-shows. If the reminders never arrived, the survey may not arrive either — which is itself the answer. If it arrives and people tell you they meant to come and forgot, or that they were waiting for the recording, your inbox is working fine and your problem is somewhere else.

2

Check whether the same people register every month (42 points)

A comms specialist asked it directly: are the registrants mostly the same people each month, and who is actually showing up versus not? A recurring audience that stops attending is a fatigue or content signal. A fresh audience that never attends is an acquisition signal. The two look identical inside an attendance percentage.

3

Phone a handful of them (14 points)

Phone them up and ask. Ten calls is a smaller sample than a survey and a far higher response rate, and it is the only method on this list that returns a reason in the registrant's own words rather than a checkbox.

4

Check the technical hypothesis properly (1 point)

Whether the sending IP was recently blacklisted, whether send volume increased, whether the email platform was migrated. A fresh sending IP has a higher chance of being marked as spam, so a migration alone can produce a decay curve that looks exactly like audience fatigue.

5

Compare the same two months last year (1 point each)

Two commenters offered calendar explanations for the same drop: accounting and finance users drowning in busy season, and conference season absorbing the time that would otherwise go to webinars. A two-month decline against the previous quarter is not the same evidence as a two-month decline against the same two months a year earlier.

Notice the ordering. The two answers that would actually settle the spam question carried one point each, and the answer that carried 67 does not test it at all. Run all five and you will know which question you are asking. Skip them and any answer you buy — including ours — is being bought blind.

“We have not changed our email sequence at all” — so why did 40% become 15%?

Because an unchanged sequence is not a constant. It is the same three messages sent to a different audience, about a different topic, in a different month, through an inbox whose rules moved without telling you. The thread named all four of those without ever putting them in one place.

Four things that move underneath an unchanged email sequence — each named by a commenter in the same thread
What movedWho named it, and in what wordsHow you would check it
The audience“Are the registrants mostly the same people each month, and who's actually showing up versus not?” — u/g00d_rat, 42 pointsSplit your registrant list by whether they have registered for you before, and compare attendance between the two halves
The topic“there's stuff that would get people to sign up, and then there's stuff that would get people to show up” — u/SCARfaceRUSHCompare attendance by topic across twelve months rather than by month, and see whether the low months share a subject
The calendarFinance-adjacent users “drowning in busy season” — u/Princess_Mango; conference season taking the slack — u/stem_crustyCompare the same two months a year earlier, not the two months immediately before
DeliverabilityBlacklisted sending IP, increased volume, a platform migration making a fresh IP likelier to be filtered — u/SCARfaceRUSHCompare the reminder's delivery and open rates against your own sends from six months ago, on the same list

There is a fifth thing, and no email metric can see it: whether the person ever intended to come. One operator in the same thread[6] changed who the invitation came from — a plain note from the sales rep rather than a marketing send — and reported registrations up 183% while, in their own words, “attendance stayed about the same.”

An email change that moved the wrong number

That is the clearest single demonstration in the corpus of what email is good at and what it is not. It moved registrations by a factor no reminder tactic in this research came close to, and it moved live attendance by nothing at all. Registrants and attendees are two different populations, and the same message can be excellent at producing one and irrelevant to the other. It is one operator’s self-report, with no control group.

“Text reminders my guy” — does SMS actually beat email here?

Nobody has compared them. That is the whole honest answer, and the comment itself — four words, one point[7] in a 56-comment thread — got about the reception the evidence would justify.

What is known comes from healthcare appointment reminders, which is a fair analogue (a person committed to being somewhere at a time, who often is not) and by far the best-studied. Here is the whole of it, including the rows that argue against the product we sell.

What the randomised reminder literature actually found, by comparison — and the comparison it never ran
ComparisonWhat the evidence foundCost, where it was measured
Text message vs no reminderRR 1.14 (95% CI 1.03–1.26) — a real but modest improvement. 7 trials, 5,841 participantsNot compared
Text message vs phone callRR 0.99 (95% CI 0.95–1.02) — no detectable difference. 3 trials, 2,509 participantsText reminders cost 55% and 65% less than phone-call reminders
Live human call vs automated call vs nothingNo-show 13.6% with a live staff call, 17.3% with an automated call, 23.1% with none. Randomised, N=9,835, all pairwise P<.01Not measured
Two reminders vs oneNo-show 4.4% with both a 3-day and a 1-day reminder, 5.3% with the 1-day alone, 5.8% with the 3-day alone. Randomised, N=54,066, P<.001Not measured
Two-way SMS vs standard care, on attendanceRR 1.03 (95% CI 0.95–1.12) — a null result. 5 trials, 4,374 participantsNot measured
Two-way vs one-way SMS, head to headRR 0.89 (95% CI 0.80–1.00) from only 2 trials, and on medicine adherence rather than attendance — the estimate trends toward one-way being better and is not statistically significant. On attendance only one head-to-head trial exists anywhere, too few to poolNot measured
Email vs anything at allNo trial. Not one arm anywhere in this literature is emailNot measured

The last row is the point of the page. The channel everybody in the thread is arguing about is the one channel the evidence base has never tested, and the two channels it has tested most carefully turned out to be statistically indistinguishable from each other[8].

RR 1.14
Attendance after a text-message reminder versus no reminder at all — 7 trials, 5,841 participants (95% CI 1.03–1.26)
Source: Cochrane Review, 2013
55–65%
How much less a text reminder cost than a phone-call reminder
Source: Cochrane Review, 2013
RR 0.89
Two-way versus one-way text messages head to head, on medicine adherence: from two trials, the estimate trends toward one-way and is not significant
Source: Ødegård et al., PLoS One, 2022

This table contains the evidence against the simple version of our own pitch

We sell an AI voice and SMS system. On the best pooled evidence available, a text and a phone call are indistinguishable for getting someone to turn up, two-way texting against standard care on attendance is a null result, and the only head-to-head pooling of two-way against one-way does not favour the two-way arm. Anyone who attaches a percentage to “a conversation beats a blast” is making it up, and if we did it you should hold it against us. Our argument rests on something else entirely — what the message asks the registrant to do — and it is set out with its own evidence and its own gaps on how to increase webinar attendance.

One row does support a change worth making, and it is not a channel change: two reminders beat one[9], at three days and one day out, across 54,066 randomised patients. The operator in this thread was already sending three.

“Email down, WhatsApp up. You have to use what people use.”

It is a real argument and it carried one point[10]. A second commenter in the same thread suggested exploring WhatsApp notifications where phone numbers are collected[11]. Neither attached a number, and there is no WhatsApp arm anywhere in the trial literature above either — so the honest status of this one is identical to the honest status of email: widely asserted, never measured.

The deeper problem is that every version of this argument treats the pipe as the variable. The table above is six comparisons of pipes, and the largest gap in it is not between two pipes at all — it is between a live human call and an automated one down the same wire[12], 13.6% against 17.3% no-show across 9,835 randomised patients. What changed there was what the call did, not what carried it.

Which is the whole reason we are not in the business of telling you email is dead and SMS is alive. The one intervention in this research with large randomised support changed what the message asked the registrant for, and it works on any channel that can carry a question and receive an answer. That argument, with its sample size and its unmeasured gap, is on the attendance page.

If reminder emails are not dead, what are they bad at?

Not delivery, and not cost. Email remains the cheapest way to put a link and a calendar hold in front of a large list, the operators in these threads are already sending three of them, and nothing above suggests removing one. What an email sequence cannot do is narrower and more specific than “dead”:

  • It cannot come back with an answer. A registrant who opens every reminder and does not attend looks identical, in your reporting, to one who intended to come and was pulled into a meeting.
  • It cannot tell you who is not coming. Opens and clicks measure whether the message was received, never whether the person plans to be there.
  • It cannot ask for a micro-commitment. A one-way blast reminder can restate the time. It cannot get the registrant to state, in their own words, when they will join and what they will be doing right before.

That is the gap we work in, and it is a narrow one, deliberately. You run a webinar. We come in and increase your show-up rate and your post-webinar sales, with our AI voice and SMS system — and the second thing you get is that you finally know why every registrant signed up, in their own words, which is the one output no email sequence has ever produced.

Frequently asked questions

You run a webinar. We come in and increase your show-up rate and your post-webinar sales, with our AI voice and SMS system — on top of the email sequence you already run, not instead of it. If that is worth twenty minutes, book a call. If you would rather keep reading: the reasons registrants themselves give for not attending are ranked on why registrants don’t show up, and the biggest lever anyone in this research reported is one we do not sell — does charging raise show-up rate.

JB
Justas Butkus

Founder & Operator, CallHush

Founder and operator of CallHush. The offer is one sentence: you run a webinar, and we increase your show-up rate and your post-webinar sales with an AI voice and SMS system. CallHush has no closed clients yet — the first engagement is a pilot run as a split of the client’s own registrant list, and nothing on this site is presented as a client result.

View all articles