How Print Book Discounts Help Your E-Book Sales

Recently I published my Kindle E-book "How To Make Easy Money Selling Your Old Used Books On Amazon" as a printed paperback (via CreateSpace) and I noticed an unusual side benefit in the process. Check out this screenshot of my updated sales page once the Kindle and print versions had been linked together:

I was surprised to experience an increase in e-book sales once the $8.95 paperback price showed up on my Kindle sales page. But it's not that it was listed; it was listed and crossed out.... then the total savings amount and percentage was listed beneath my retail selling price for my e-book.
I believe that this one change helped create more value for the e-book. It's like the browsing buyer has been given another version to buy; it appears that my book is on sale (it's not). Moreover, I quickly sold 2 paperback versions of the book on CreateSpace.... netting me $3.22 per copy, with no extra work required on my part at all.
So far I have two of my Kindle books converted into printed paperbacks. After this experience, I'm certain I will always have a print version available.
The great thing about CreateSpace is that it's POD (Print On Demand) delivery mechanism allows an author to always (always, as in forever) have the most updated book on the shelf for sale.
This is important to keep your work current, relevant, and not piss off the customer. I browsed some paperback book titles just yesterday and found several very interesting titles related to one of my niche subjects... yet, they had been published in 2006, and more than half of those helpful tips and techniques were obsolete. Thus, the tens of thousands of dollars a publisher had spent to turn paper and ink into products was in effect wasted; the excess copies held no value for me... and judging from the recent book reviews as early as 2009.... readers were not kind to this book, driving down the average review simply because the information was old. Outdated. Not current.
And my point in all of this? The new publishing platforms KDP and Smashwords and iBooks and no telling how many future e-book publishing delivery systems are forever changing the way authors are published and compensated.
Having a printed version available not only brings in extra revenue -- the natural discounting feature Amazon employs helps create the appearance of real savings to browsers. The end result is that more browsers become buyers, more Kindle books get sold, and authors make more money.