Originally Posted by Doitsu
I find it somewhat strange that someone who doesn't even own a Kindle suggests creating .mobi files that only a small number of Kindle users (and owners of other ebook readers with .mobi support) can actually read on their devices.
BTW, you're wrong as far as the file size is concerned. For testing purposes I compiled your ePub version of “War of the Worlds” with KindleGen 2.4 and Huffdic compression (-c2). After stripping the .mobi source files both files were almost equal in size: ePub = 1.96MB; mobi = 2.11MB
For good measure, I did the same conversion in Calibre: mobi = 398KB; azw3 = 2.05MB
As the numbers clearly show, it's definitely not the mobi part that leads to overly bloated files, because in most cases you could easily include the regular mobi version without a significant increase in file-size.
I don't use KindleGen. I use Calibre to do the conversion. So please redo your math based on Calibre's output.