I tried to include two links to Amazon in this answer, one to the amazon.com page of a book and one to the amazon.de page of the same book. (This made perfect sense, since the two pages contain different book reviews, all in English.) In the edit preview, the links worked. However, in the submitted answer, they both got replaced by this link (though the original links were still there when I edited the answer again). Apart from the fact that I strongly prefer to decide for myself what links I put in my answer and find it disturbing that they get changed behind my back (after all, people will attribute those links to me and not to the machine that replaced them), in this case it broke the content, since the two links that were supposed to point to different pages with different reviews now pointed to one and the same page. My questions about this are:

1. What is the rationale for rewriting the links?
3. If there is a good answer to 1, is it compatible with that rationale to do what I did, namely to use a tinyurl instead of the Amazon URL to circumvent the rewriting?
• Just a guess: maybe stackoverflow makes money this way? (And: +1 for the find!) Jul 15, 2011 at 19:50
• See this MSO question and many others. (originally posted 5 mins previous, but deleted and reposted so I can fix a typo). Jul 15, 2011 at 21:38
• A slightly simpler workaround than a url-shortener is to use percent-encoding. Replace e.g. one period by %2E. Compare Direct link www.amazon.com/... and Encoded link www%2Eamazon.com/.... See also my deleted answer below.
– t.b.
Jul 16, 2011 at 4:25
• Perhaps the rewriting doesn't occur in comments and/or on meta? (They're not literally identical; one does have a percent-encoded period and the other doesn't; but I guess the idea was to show that the non-encoded one gets rewritten and the encoded one doesn't?) Jul 16, 2011 at 18:03
• @Bill: as joriki said, the links aren't literally identical, but yes, you're right, they didn't get replaced in the comments [interestingly]. However, in my deleted answer below, the two non-encoded links did get replaced while the the encoded ones were replaced. (They didn't break, though). Sorry about that, I should have checked the links in my comment more carefully.
– t.b.
Jul 16, 2011 at 22:38
• @Theo, @Joriki I figured out the problem. Unlike FF, it appears that IE unencodes the %encoding before copying urls, so I wasn't able to see the %encoding in IE simply by copying the url. Jul 16, 2011 at 23:00

1. Yes, StackExchange is an Amazon affiliate. If someone clicks on the link you provided and buys the book, StackExchange gets some money for referring them.
2. They have a "cunning plan": to facilitate actual ordering of books, the link geo-locates where the link-clicker is based (using the IP address) and links to the appropriate Amazon store for the locale. (So presumably someone in Germany would get the amazon.de address, while someone in the UK would get the amazon.co.uk address, when accessing the "same" link.) Cunning plan vetoed by Edmund. (See comments below.)
3. Well, since your link to the review is especially for the purpose of supporting your assertion of there being a misprint, rather than as an actual book recommendation, I guess it is reasonable.
• well, we used to do #2, but we don't any more because Amazon requires you to have a physical business location in every country that products are sold from. Jul 16, 2011 at 2:19
• +1 For Baldrick!
– Asaf Karagila Mod
Jul 16, 2011 at 7:20
• Thanks for the answer, Willie. Here's a link about the geolocating being discontinued: meta.stackexchange.com/questions/75594/…. (I was wondering why it wasn't working for me -- since I am in Germany :-) Jul 16, 2011 at 12:14

The Amazon redirect links will no longer touch links that are not to the US .com site.

See