Book Promotion: Be sure to get a final jpg image of your book cover for advertising and website display.
Be sure that once your book cover had been designed and ready for the printer, that you receive a jpg image of your finished cover… several in fact. One at 300dpi final book size, if your book is 5.5" x 8.5" then that is the size of this jpg. From this image all other images for use on your website or for advertising can be made.
Each specific use will have a specific size and dpi requirement.
Most images used on a website are 72dpi and can vary in size.
Thumbnails are usually about 1-2...