It can be, and the first step is publishing your book. This book will guide you step by step through the process, from initial research to how to market your book.
Don’t think you are a very good writer? I will show you how outsource your ideas to other writers who will write the books for you. All you need to do is publish them. And collect the checks.
I will also divulge a secret niche which sees extraordinary sales and searches on Amazon. There are very few writers taking advantage of this trick, and those who have are seeing their books in the bestseller lists.