Kickbacks to other web pages, perhaps. I've never heard of kickbacks to
Usenet posts. Do you have a cite for that?
If someone sets up an account with Amazon for referral fees and then
uses a properly coded URL *anywhere*, and that generates clickthroughs
and especially sales, they get referral fees. It is usually, but does
not *have* to be, a Web page. And obviously it can be indirect: put
Amazon link on Web page; aggressively promote Web page elsewhere in
turn. Amazon links are nearly as common as AdSense blocks on blogs
whose URLs are heavily spammed; I wonder why? I've seen one or two
that were nothing *but* Amazon links. Now here we have a usenet post
pushing people to a Web page with very little on it but a book ad with
a single link ... an Amazon link.
Of course it *proves* nothing. It may indeed turn out that there's no
direct financial benefit to the usenet poster in question after all.
Even so, all of my *other* points stand, particularly regarding the
non-mentioning of the well-known-to-regulars-here free materials on
the subject and non-mentioning of the fact that the link supplied is
to an ad rather than directly to directly-relevant information. I, for
one, hope that if I ever post a concurrency-related question here and
someone posts a URL labeled "concurrency in Java", that it will lead
to a Web page directly containing tips and helpful information
regarding threading in Java, rather than just to an ad for where I can
*buy* some several kilograms of dead tree containing such information
and wait four to six weeks for delivery.
