yes, please provide a pdf version (free or paid, doesn't matter for me) ... oftentimes authors will make a kindle version of the book for sale on Amazon and forget to put out a pdf.
Where do most people go to buy PDFs? Is it really a large-enough market to worry about?
Other than that, all the ebooks I've bought from individual storefronts, often from having seen them on HN, have come as a PDF/epub/mobi bundle to work on any device.
If it's not DRM protected, but rather a "secure" PDF, you'll need some other tools that can remove the owner password. About.com has a list here: http://pcsupport.about.com/od/toolsofthetrade/tp/pdf-passwor...