Google Books is like the biggest Christmas present evar!
There are lots of little gems to be found in it.
One of them is from the November 1917 issue of a monthly called Modern Methods.
This periodical was aimed at businessmen (they were mainly men then), filled with practical advice about things like selling, organization, import/export, and other practical matters.
So it’s the last place I would have expected to see a full-page ad for something so un-businesslike as a collection of stories!
Yet there was a full-page ad for a collected set of Mark Twain’s works!
This is the ad as it appears in the Google Books PDF:
And this is an enhancement and enlargement of it so all of the tiny text can be read when it’s been clicked on (and I suggest you do; there’s something in it that will make you laugh for its cheek!):
It seems to me that at one time book publishers actually courted readers, not bookstores.
They need to return to that.