The Size of Your Catalogue on Amazon Counts.
If you publish five ebooks on Amazon, you will sell. If you publish 50, you will sell more. That’s logical. In some genres of fiction, short story writers report that it takes a catalogue (your “publishing catalogue” is the number of books you have under one name on Amazon) of 30 stories to make enough money to pay some of your bills each month.
So whatever you write, focus on writing and publishing. Do the best you can for your readers. If you’re writing fiction, provide entertainment that’s worth $2.99 or $3.99 or whatever. If you’re writing nonfiction, give readers information that’s worth what you charge.