All you have to do is take the content you have already created, make small adjustments in the wording, add examples specific to your new target market, and Presto! How would you like to create a Kindle book once, and with minimal work, create new books, one after the other. That’s what you can do when you pick a market with lots of niches. Remember that Kindle books don’t have to be big tomes. You can keep them fairly focused on one problem at a time that people want to solve.