
No Emails on Saturdays - latitude
http://swapped.tumblr.com/post/43344145251/no-mail-on-saturday
======
latitude
OP's here.

A couple of things I forgot to mention in the post.

1\. The numbers are based on hits through URLs with tracking information. Some
visited and voted from the Twitter feed, some hit the base URL. This affects
absolute numbers, obviously, but the %-ages should be about the same.

2\. I also tallied up negative and positive votes, thought that perhaps people
on Monday were more stressed and negative than on Sunday. But there were too
few dislikes, so it's hard to make any conclusions -

    
    
             like    !like
      Sat     22       3
      Sun     44       3
      Mon     34       1
      Tue     34       1
      Wed     35       4
    

EDIT - I added raw emails/opens/votes data at the end of the Tumblr post, just
in case.

------
dantiberian
There is email campaign software available that tracks the open times on
previous emails to each person on your list. The next time you send a
newsletter to that person, the email is sent at the optimal time for the
person to open, read and interact with it. I forget what the software was but
I always thought it was a great idea.

~~~
benihana
While at Bronto software (<http://bronto.com/>), one of the features I worked
on was just that. We called it Send Time Optimization, and from what I
understand, it's not an unheard-of feature amongst email software providers.

~~~
weeksie
Completely off topic — you worked at Bronto? I did a short (like 1 or 2 day)
contract to write a first pass at their Ruby client gem a couple years back.
Seemed like nice guys. I get shivers thinking about Ruby and SOAP though.
Eesh.

------
birken
Thumbtack has an open-source split testing calculator which makes it very easy
to see whether or not results like these are significant or not:

[http://www.thumbtack.com/labs/abba/#Sunday=47%2C389&Tues...](http://www.thumbtack.com/labs/abba/#Sunday=47%2C389&Tuesday=35%2C378&Wednesday=37%2C400&Saturday=25%2C401&Monday=35%2C379&abba%3AintervalConfidenceLevel=0.95&abba%3AuseMultipleTestCorrection=true)

If we treat "Sunday" as the baseline and use "votes" as the count of a
successful email, it appears that you can say with a somewhat high degree of
confidence that Sunday is better than Saturday, but nothing else.

~~~
gus_massa
But with the opening rate, there is a totally different story:
[http://www.thumbtack.com/labs/abba/#Sunday=157%2C389&Tue...](http://www.thumbtack.com/labs/abba/#Sunday=157%2C389&Tuesday=175%2C378&Wednesday=177%2C400&Saturday=111%2C401&Monday=148%2C379&abba%3AintervalConfidenceLevel=0.95&abba%3AuseMultipleTestCorrection=true)

------
dmor
One other thing I think you should experiment with is time of day. There was
another great post (not able to find the link yet, will update when I do) that
talked about open rate being highest within the first few hours of sending
_regardless of the send time_.

I've always been a fan of sending between 3-6am, although I think I just took
this as a rule of thumb from someone I worked with an never questioned it
much. Would love to see a similar study on send times within the optimal range
of days.

~~~
Samuel_Michon
MailChimp has a neat page where they list the average open rates for the 5.5
million mailing lists people manage using MailChimp's platform:
<http://mailchimp.com/resources/research/>

"Most emails are sent between Monday and Friday, with the highest volume on
Tuesday and Thursday. More subscribers open email, however, on Wednesday and
Thursday."

"Subscribers are likely to open email after 12pm, and the most active hours
are 2-5pm."

"Your newest subscribers are your best subscribers. They’re most engaged
immediately after signup, and then trail off over time."

Those are averages though, your mileage may vary. For the newsletters I send
out, Tuesday morning has proven to be the sweet spot.

More information: [http://kb.mailchimp.com/article/when-is-the-best-time-to-
sen...](http://kb.mailchimp.com/article/when-is-the-best-time-to-send-emails)

------
madnessjames
What time of the day you send the email makes a big difference. Especially if
your list is large. ISPs do magic with large sends to prevent spamming. If you
send on a Sunday evening, and others send Monday morning at 3am for example,
most people's email view is reverse chronologically ordered. So on Monday
morning, your email is likely to be on the bottom of the pile.

------
Mamady
Your sample size it way too small for the stats to be meaningful

~~~
latitude
Excellent, I see.

So you are saying that if I had 10x the data, then the Saturday opening rate
and the Sunday response rate could've been completely different?

~~~
ihaveajob
Your margin of error is 4.38% [1], which makes the comparison between all non-
Saturday meaningless. However, it seems like the numbers for Saturday vs other
days are useful.

To answer your specific question, if you had 10x more data, your margin of
error (with 95% confidence) would drop to 1.39%, so yes, you could reasonably
get fairly different results.

I was disappointed to read that you skipped Thursday and Friday. In my domain,
Mondays are the peak of activity, slowly sliding down to a bottom on
Friday/Saturday. I would have liked to see your numbers for every day. Next
time! (In that case, your MoE would have been 5.37%, btw.)

[1] <http://americanresearchgroup.com/moe.html>

~~~
latitude
I am too very curious about Fridays, but I suspect it would require getting
the time of the day right too. Send it too early, and it's pre-weekend morning
stress. Too late - and everyone's already gone for the day.

PS. I don't know why I picked (mod 5). Makes zero sense now.

------
Aardwolf
Interesting stats, but I'd love to see this with a bigger sample size, and
with thursdays and fridays included!

------
andrewcooke
are the engagement numbers for sunday correct? it appears to be highest, which
doesn't match the conclusions.

[edit: maybe i'm not understanding, but engagement on sunday is _highest_ at
47, yet the final recommendation is for "Tuesday or Wednesday" (35 and 39).
why wouldn't you choose the day with highest engagement?]

[also, incidentally, those numbers are all the same to within a couple of
standard deviations (1 sd ~ sqrt(n) ~ 6). so the sample size is too small to
draw any really firm conclusions.]

~~~
timv
It looks like the conclusion is overly simplistic (but it's a blog entry based
on a single experiment, so it's quite reasonable to limit it to simple
conclusions)

If I understand the data correctly, Sunday has a low open rate, but of those
that open, it had very high engagement rate.

The author seems to be saying that the open rate is low enough to make Sunday
a "bad day", but that really depends on what your email is about.

If getting people to read the email is your priority, then avoid Sunday, but
if you mostly care about getting them to respond in some way, then Sunday
could be good - those that read it will have the free time to actually
respond.

(Of course, while the limited data provided by this experiment is interesting,
it's probably not worth basing any serious decisions on)

~~~
latitude
What I wanted to share was the fact that there _was_ a noticeable difference
to begin with, so it's something worth paying attention to.

The exact pattern will depend on the audience. If it's VmWare emailing IT
people, then the open rate is probably going to be the same through the
workdays and zero on weekends. If it's some hobby stuff, then it'd be in
reverse. For my particular project, it just happens that Saturday sucked,
which is a good thing to know.

~~~
timv
I certainly think that your experiment has value - my apologies if it came
across any other way.

\- If nothing else, it shows that there is a difference, and the day you pick
for your newsletter matters. \- It seems that it would be helpful for other
people to repeat your experiment (but stretch it to 7 days) to see what the
results are for their readers. \- The difference between the open rate and
engagement rate is quite interesting.

------
mansigandhi
Very interesting, thanks for the share.

------
baby
Isn't there a statistic somewhere about facebook, that people go there the
most on wednesday 17h?

------
angelohuang
Does this number also apply to Tweets? Maybe someone can tell their experience
on tweets.

~~~
bradleyjoyce
We do this for Twitter at <http://socialyzerhq.com>, but rather than just
limiting to historical data we try to predict when to send in the future.

------
totalrobe
Why no Thursday/Friday? Those are slower days at many work places.

