I read a lot on non-fiction and the books usually have an index. One way of finding trigger words is scan the index and look for words that have a lot of entries. Foe example, in a book on the stock market that I am attempting to PR, the term "support-resistance" is spoken about 62 separate times in the book - must be important. Combine these words with chaper/section headings, 20-25 words should be easy to find.
Fiction is another story. I find it very difficult to come up with appropriate trigger words.
Michael
