I am currently researching what ebook formats I should be targeting. I would like maximum distribution potential with minimum fuss (for both myself and users, with the latter taking priority). I have noticed that some sites provide both .azw and .mobi files while others opt for one or the other. According to Wikipedia, Amazon's file format offering is just a lightly modified version of the Mobipocket format. I also know from my own Kindle usage that I have never had a problem using Mobipocket files on it. I also believe there are other readers that can handle this format but not Amazon's native one.
Is there is any advantage to providing .azw or .kf8 formatted content if I am making .mobi files available anyway? Would this just me added clutter to my interface and product offerings or would is there something to be gained from the extra format? I will be making .epub and perhaps other formats as well so this question is just about the best way to support Kindle readership.