(AIDA -The History bit 1890s? 1904? Or 1921? according to Wikipedia
E St Elmo Lewis in 1890s came up principals for an effective advertisement.
The general concept of four steps, however, was in an article by Frank Hutchinson Dukesmith in 1904. Dukesmith's four steps were attention, interest, desire, and conviction.
The first instance of the AIDA acronym was in an article by C.P. Russell in 1921 where he wrote:
An easy way to remember this formula is to call in the “law of association,” which is the old reliable among memory aids. It is to be noted that, reading downward, the first letters of these words spell the opera “Aida.”
"..When you start a letter, then, say “Aida”to yourself and you won’t go far wrong, at least as far as the form of your letter is concerned.."
(the principles still apply to electronic mail)