Russell Beattie played with the Kindle (http://www.russellbeattie.com/blog/mowser-on-kindle) and posted the browser header that it uses when browsing the Web:

HTTP_USER_AGENT: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 4.0) NetFront/3.3
HTTP_X_FSN: ABC123ABC123ABC123ABC123ABC123ABC123ABC123ABC123*
HTTP_X_FORWARDED_FOR: 66.193.201.11, 10.0.52.11
HTTP_VIA: 1.1 (amazon proxy)
HTTP_ACCEPT: image/png, image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, */*

Did you know that it was powered by NetFront (http://www.access-company.com/products/clientsuite/index.html)?

Yep, we did.

Yep, we did.

Good. ;)

What is the meaning of the HTTP_X_FSN header?

Also, does anyone know how the CDMA location gets communicated to the server?

Thanks,
Julien

What is the meaning of the HTTP_X_FSN header?

My wild guess? Fiona Serial Number. The linked posts say "* The ABC123 stuff above is in place of some identifier info that Diego would rather I leave out, for understandable reasons. :-)" and the letters line up correctly in that case.

Hmm so there's a proxy ? In this case I can't exactly know how many people are using Feedbooks on their Kindle :-/

You still could know how many people are using Feedbooks by looking at the FSN number? Otherwise setting a cookie be an option (if the Kindle browser does support cookies).

Cheers,
Julien