Interesting read about the Post services and the cost structure they have been handling with the years. Sending an international letter, although not very often, looks like such a simple transaction. But it was interesting to realize that sending letters was initially a privilege and then became main stream and the only way of communication until not far ago (thanks internet with emails, etc etc). And then you had an international organization to deal with the mail exchange between countries. At the end, it is a comparison exercise between the cost of mail and the cost of using internet. Enjoyable read about history and related to the internet.