If you bought a washing machine that failed to clean your clothes, you would feel entirely justified in demanding a replacement or, at the very least, a repair. In today's consumer society, we expect products to work. When they don't, it is regarded as an aberration.
However, these rules don't seem to apply to self-help books. I remember selling a one or two self-help books a week to the same woman for nearly three years. She must have bought over 200 books from me on a variety of subjects. She ran with the wolves, did the dance of anger, walked along the road less travelled and discovered that she was from Venus, but after two years she didn't seem any better for it.
I had similar experiences in other bookshops. Women (for it was always women) would religiously (or irreligiously) buy one self-help book after another without displaying any discernible change. This seemed strange, given the books' grandiose claims. Normally, if you buy something that doesn't work, you don't make the same mistake again.
The typical self-help customer hasn't been to university. They are in their mid-30s or older and have lived long enough to experience a creeping disillutionment with their lot. Perhaps their kids don't understand them and the young Adonis they married is now Homer Simpson. They have no intention of walking out, so their focus is on how to make life more bearable.
Of course, it's entirely possible that I'm wrong. Perhaps these books were so effective that the customers simply wanted more, or maybe their angels told them. Either way, it sounds like money for old rope if you're a publisher and I'm amazed how successful self-help and MBS (Mind, Body and Spirit) books are.
And why is it nearly always women who buy these books? My wife's theory is that it's because they live with men. I'm not quite sure how to take that.