POD is just never going to have a great profit for the author. Printing a single book at a time is more expensive than doing a print-run of several hundred/thousand.
I think RC is right. The economics of paper books are very different. I've got two, now three paperbacks available at Createspace and Amazon. Most paper purchases were made by friends who don't like to use e-readers. A few other sales were to folks I don't know and I was shocked to see two paperback sales the other day (two different books)
On the other hand, I've been pretty lucky with the digital side. I've been selling ebooks (primarily Kindle format) pretty regularly. What really surprised me though was the number of audio books I sold. Some days, I sold more audiobooks than I did ebooks. Audio is way more profitable for me than paper. I'd encourage eveyone to look into audiobook editions for their books. Royalty share deals cost nothing except time and the expense, if any, of a reformatted (square 2400x2400 pixel) cover. You can audition narrators and if you don't find one you like, you don't need to go any further with it.