They don't need to add a monthly charge, but they could for example sell Internet access per megabyte, for example $0.10 per megabyte or less, just as that is what they charge per document that is converted and sent to the Kindle email.
So for example you could add something like $5 of bandwidth to your account to access for example 50mb of books from Gutenberg.org, Google Books, from any RSS feed in the RSS aggregator, a smart personalized version of Google News and that per-megabyte charge would probably be the one to use for browsing using the browser when it's not experimental anymore.
Hopefully $5 could give much more than 50mb bandwidth on EVDO, on HSDPA in Europe for example, I would expect 5€ give access to at least 1GB of bandwidth. Just as Amazon is used to charge for bandwidth on their Amazon S3 service, this is the same deal here. Downloading a book conveniently from Gutenberg.org in a nice optimized interface, if the book is for example 200KB would thus cost $0.02 if the price per MB is for example $0.10.
Last edited by Charbax; 11-22-2007 at 08:29 AM.