Use mobi on Kindle and Nook
Download the .mobi ebook for Kindle to your computer (epub will not work on Kindle).
Connect Kindle to your computer with a USB cable. This will mount Kindle as a USB flash drive.
Copy mobi ebook into either the books folder of docs folder. Note: when opening ebook to read it may only be accessible from the docs folder.
Unmount Kindle before disconnecting from your computer or you may damage the data.
You can now use your ebook on Kindle.
Email mobi to Kindle
If you have an active email account on Kindle you can email mobi ebook to that account.