Most non-fiction has a recursive introduction, body, conclusion structure. The nature of the structure varies a little from author to author, but can be identified pretty quickly. In pop non-fiction (and especially in business/management/productivity non-fiction) at a certain depth in the tree the body will be entirely filler and can be skipped wholesale. This is how I "read" most non-fiction now: first and last paragraph of each chapter (or section), first sentence of each paragraph in between, if something strikes me as particularly interesting or unintuitive I'll backtrack and read the full paragraphs before and after. Once I've done a first pass like this I'll decide whether I want to go back and read the full thing word-for-word. Typically the answer is "no."