Many of my stories are available via two methods. First, as a PDF download from here and second as an inexpensive purchase in the Kindle format on Amazon. Kindle format works with Kindle devices and also via the free Kindle app available for Mac, PC, many tablets OSes and as a web based application too.
So, why would a reader want to buy a story when they can download for free? Kindle format displays much nicer on Kindle devices than a PDF does, although both work, but the most obvious reason is that you enjoy my stories and want to support my work and encourage me to keep writing.
At the very least, if you liked the story I would not object to a good review (hint, 5 stars!) on Amazon. 🙂