The term "log rolling" entered my consciousness perhaps 25 years ago, when one of the national magazines (Esquire? Time?) used it as a header on a column that outed authors for touting each other's books in blurbs. You praise my new book, I'll praise your next book.
Evidently the term is quite old as there is a reference to author "log rolling" in an 1877 edition of The Saturday Review.
So, without further ado, here are some of my friends log rolling for me and my new book: