"Ben is struggling. Ben changes his usual routine and starts doing X. Fast forward a few years, and now Ben is successful."

Therefore, authors conclude, doing X will also make you successful.

That seems like a good formula self-help book. It reminds me a little of how medicine was performed up until the 20th century. People were given a treatment, and if it seemed to have a positive effect, it was given to everyone. But the problem was that lots of medicines were placebos. This changed thanks to better statistics and hypothesis testing.

I'd love to read a self-help book that does real hypothesis testing about their treatments, instead of presenting anecdotal evidence. It would be a great book no matter what.