For many self-publishing authors Amazon is their best friend in the world of self-publishing. Amazon has leveled the playing field and given authors access to readers and with CreateSpace allows the author to physically publish their own paper books at affordable prices using the print-on-demand business model. Given the prominence of Amazon in the self-publishing world, it is no wonder that Kindle books are prominent in many authors minds when considering entering the world of e-books.
I urge authors to look into Smashwords as well if considering an e-book version of a title. Kindle is Amazon's proprietary e-book reading system. Smashwords is a company that allows authors to publish e-books in ePub and a variety of other formats. Just as CreateSpace grants its authors direct access to the marketing and distribution of Amazon, Smashwords provides that access to a wide range of other distribution points, such as Apple, to the e-books sold through Smashwords.
Better yet, for those interested in learning more about Smashwords, the company's site is very user friendly! Also, the royalties paid by Smashwords are excellent and in some cases as high as 85%, better even than the 70% offered by Amazon for titles that meet Amazon's requirements for a 70% author royalty.