In short
Between 7 May and 17 October 2026 we sent 9,934 letters to 3,111 people. Most went to our list, 262 were written to people we chose one by one. A letter to our list was opened about one time in five; a letter to someone we chose was opened three times in four. The German list opened far more than the English one, and most letters that were opened at all were opened within a day.
This note shows what we measured, why an open is a softer number than it looks, and the one rule we made after a letter taught us nothing.
How we write
We write to our readers rarely, in the calm voice of a letter: a greeting, a few paragraphs of whole sentences, a warm last line. No one on our list receives more than one letter from us in seven days, and every letter to more than a handful of people goes out with a record of whether it was opened and whether a link was clicked. Letters to our list go only to people who have said yes to them.
Two kinds of letter
Letters to our list and letters to people chosen one by one
Letters to our list were opened 20 percent of the time, and a link was clicked in 1.3 percent. Letters written to people we chose one by one, a stage we would like to dress, a hotel we would like to work with, a journalist who writes about our field, were opened 76 percent of the time, and a link was clicked in 11 percent.
The difference is larger than any change of subject line could make. A letter that is written for one person, and says why, is read.
German and English
The same letter, in German and in English: share opened
Five times we sent the same letter on the same day in German and in English. Each time the German letter was opened more often, in four of the five cases more than twice as often.
We cannot say from this that German readers open more. Our German list is much smaller than the English one, and the two lists are different people. The figure shows the lists as much as the language, and we would need a letter sent to one list in both languages to tell the two apart.
When letters are opened
When a letter to our list is opened, counted from the moment it was sent
Of the letters to our list that were opened, 38 percent were opened within an hour and 77 percent within a day. After three days only one open in eight was still to come. A letter that has not been opened by the third day will most likely stay closed.
Why an open is a soft number
An open is recorded when a small image in the letter is loaded. Some mail apps load images on the reader's behalf, whether the letter is read or not. Of 2,097 recorded opens, 645 came with a bare browser signature and no device named, the kind such apps leave. An open is therefore an upper bound, and a click is the firmer sign that someone read.
What we learned
A letter without a record teaches nothing. On 18 September two letters went to 91 people from scripts written by hand, without the small image that records an open. We will never know who read them. Since 21 September every letter to more than a handful of people carries that record, whoever sends it and from whichever address.
Asking is kinder than guessing. Of our addresses, 1,589 had received our letters and never opened one. On 17 October we began asking them, once, whether we should keep writing. Whoever opens or clicks comes back to our list; whoever does not will not hear from us again. It is too early to report what they answered.
The few letters written for chosen people carry the most. The letters chosen one by one were under 3 percent of what we sent and brought 28 of the 149 clicks we recorded.
What we would like to know
What makes a calm letter opened and read is one of the open questions on our research page. Students who would like to work on it are welcome; we share open and click rates per letter in aggregated form, with the subject lines and the letters themselves, never an address or a name.
Sources
The figures come from our own letter log in the Studio, read on 18 October 2026: every letter marked as sent between 7 May and 17 October 2026, grouped into letters to our list, letters to people chosen one by one, the question to readers who never opened, and the two letters sent without a record.