An anecdotal story to back up the authors point;

I live on a boat, and have done so for 8 years. I know quite a bit about what it takes, what the difficulties are, what to look for when buying a boat, what to do about heating in the winter, etc. etc.

I've thought about writing an e-book about it to give others an insight into what the life is like, how to do it, what it costs, all sorts of practicalities, etc. But I don't think I'll do it after having researched what I can expect to make on it.

It's simply not worth my time because it seems like people on the Internet generally aren't that willing to pay for good content.