The Heath brothers looked at why a few ideas stay in your head for years while most are gone by the next morning. The ones that stay are simple, surprising, concrete, and carried in a story instead of a list of points.
The acronym they hang it all on feels forced, and the book is longer than the idea needs. It is still one of the most useful things I have read, because it applies to everything. Every pitch, every landing page, every explanation to a customer. Since reading it I cut about half of what I write.