I forgot to provide an update to how I was doing with Kindle. The answer is that I'm doing very well. Most of my business has shifted to Kindle as a result. All you need to do to succeed is to continue writing and publishing fiction books in as many niches as you possibly can. Make sure they are novels, have an excellent cover and that you charge at least $2.99. Do not overthink. Do not care about reviews, what other people's niches are, how many books someone else wrote, how much money another author is making etc. Just write and publish your first book NOW if you haven't done so. Then write and publish another book even if the first one didn't do well. Eventually you will dominate.