Hi,
First of all, thanks for the info. I'm using 3 devices (a kindle, a pc, and an adroid smartphone) for reading and using this method I can finally sync my books across devices.
I've did some experimenting, and it seems, the ASIN doesn't even has to be valid. I've managed to sync my 3 test books using bogus numbers like "B000000001", "B000000002", "B000000003", and so on. The only problem with this, that the android app is downloading some random images from amazon as book covers
. Tomorrow, I'll try it big. 500 books, from "B000000001" to "B000000500". I'll report back about it.