I do make good money from kindle publishing, but I have been writing in the same genre for five years, and have spent the same amount of time building up an audience who like what I do.
The key to making sales with Kindle Publishing, is you have to first do the basics - write an awesome book, have an eye catching cover, create a blurb that encourages readers to want to read your book, and make sure that same book is well edited and formatted. Those basics are essential if you want to build and keep your audience of readers.
And that’s only part one. In part two you have to drive potential readers to your sales pages on Amazon. Just because Amazon has millions of site views every day does not mean your book page will get any. You have to assume that nobody is going to “fall over” your book while they are searching for their next buy on the site. You have to encourage people to click on the links you provide on other promotional platforms, so they will buy.
Saying that, you can’t just plaster “buy my book” adverts on social media groups. That doesn’t work either. Facebook advertising has a low rate of return (in my experience, it may work better for specific genres) and Amazon advertising is even lower. Many new authors don’t have the money to spend on advertising anyway and use more organic methods of driving sales of their books.
One of the key organic ways of increasing sales is to have your own blog and newsletter, and set up your own group on FB. You can also join other groups related to the genre you are writing in, but again, don’t just put out “buy my book” posts. Join in, be active, offer advice and ask questions. Friend other authors in your genre and promote their books on your profile when they come out. Authors will often reciprocate when your book comes out.
One last tip if you want to make long term money from kindle publishing is to write more than one book. If you write fiction, create a series of books. If you are a non-fiction writer then write various books that all link up on similar topics. It is very rare for any new author to make a huge ton of money on one book, but you can build a sustainable long term income by writing a number of books over a period of time.
Good luck.