Email + Regional Book Agreement & Amazon ebook prices
First @ Ian Michael Gumby - The 'email' part of the lending is detailed in the linked Amazon site. The emailing is used for an authorisation, for use by another user of the ebook owner's account. Then the database for the ebook loan is flagged, to authorise use of the loaned ebook by only one reader at a time.
Regional Book Agreement
Although the principle of lending/borrowing and library use is basically the same in the the USA and UK, restrictive practises by the publishers that operate under their Regional Books Agreement cannot be justified any more.
Amazon operates data services commercially. I guess that they use server load balancing that probably often involves shifting data across server farms based in different continents, including moving their own data.
In practise if I buy an Amazon-UK ebook that I cannot buy from Amazon-USA because of the Publishers Association Regional Books Agreement, I could be downloading the ebook from the same servers in the USA that a USA based customer would also use. Amazon operating in different regions demonstrates the point, that there is no significant cost difference. The effect of the restrictive practise on the price paid is reinforced by USA based B&N that is unable to sell ebooks to UK customers, but ensures competitive USA pricing by Amazon-USA.
Amazon ebooks are essentially in the cloud. So I might not have all of my Kindle ebooks on my phone, as they are easily downloaded . But because of the Regional Books Agreement if I buy a book from Amazon-UK, in effect I cannot lend it to myself while temporarily in the USA, which I might want to do in order to get it onto a phone. Plainly daft.
But here's the thing also - have you compared the ebook price for the same book on Amazon-USA and Amazon-UK or B&N ? The Amazon-UK Kindle price is usually significantly higher, and that is entirely down to the Regional Books Agreement, the greedy publishers.
Ebooks are classified as a service (now with 20% VAT) that some of the time might come from the same server for both USA and UK customers. The publishers' restrictive practises on regional pricing of services that demonstrably cost the same ought not to be unchallengeable (taxes excepted).