One way to make more money with your ebooks and other informational products is by expanding your line of products. This could be through expanding an ebook to include audio, video, kindle, physical book, etc.
An area I am looking into is grouping a group of related ebooks into a package for sale. For instance most people looking to work from home would be interested in surveys, writing, making websites, making ebooks, domain parking, and phone apps.
Rather than try and sell individual books why not group the ebooks into one package and sell it as a complete home business which it is. So by adding a work at home package of ebooks with my retire by 40 ebook is a perfect match.
Using this combination would allow almost anyone to retire without much money since they would have all areas of internet income generating passive money.