Many people ask this question while dreaming of seeing their name in print and bringing in the millions. I have news for you, this seldom happens (the millions of dollar part). But, if you tone down your dreams and work to build good, interesting, well-written books, then yes, you can make a decent amount of money publishing ebooks.
Most people who make a living wage publishing their ebooks have well over 20 ebooks up for sale. If you are aiming to make 6 digits a year, you will need to write more books - perhaps over 100 books.
The more ebooks you publish, the better. That is my personal motto.