I think that you're right, yet the book may still be valuable. I have, for a while, read summaries of business (and other) books by getabstract.com. These cover the main points of the book, but what happens is that you read it, it all makes sense, and a day later you've completely forgotten of it.

The book, on the other hand, yes, expounds on the very same points again and again, with different examples, under different circumstances, highlighting different aspects, and then, having had the same message hammered home so many times, there's a faint chance that a month later you remember some of it.

(Great books change the way you view things forever, but that happens rarely, and never with business books, I'd say :-)

Yeah I'm not really saying it's useless just that it's the basic format of those books. I think the best way to read those is to skim the various testimonials to get an idea what they're talking about and get to the author's point then read them as they spark your interest or seem relevant.

I get why they're in there, it's one of the few ways to argue the actual effectiveness of whatever advice the author is giving. It just seems excessive sometimes how much of the books are just 'I swear this works look at these important people it worked for.'

Yes, and that's a feature. Human brains are swayed by narrative, not by rote facts. If you want to get a positive change implemented, you need to tell a story.