You can skip the one click and the drama and buy my books directly through PayHip. All books offered on this site are a dollar to a dollar-fifty less than at the other places. And I offer three formats. Kindle which is mobi. Epub which is everyone not Kindle. And a PDF for those unaffiliated souls.
Warning for Kindle Mobi users:
Sometimes the mobi file will not open automatically and must be sent to your kindle device a different way. If this happens please use this troubleshooting tutorial.
And here is Payhip's guide to opening your purchases on your Kindle. SENDING AN EBOOK TO KINDLE
I've never had anyone tell me there is a problem with the epubs opening. I don't have one so I have no idea how to troubleshoot for that.