I will admit I have purchased some items I could find nowhere else on Amazon.
However, I am constantly looking for alternatives. I wouldn't say Amazon is a
"would be" threat, it is "a threat" to free software and to privacy
world-wide.
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"One day, Bezos marched into Steve Kessel's office and gave an order: "I want
you to proceed as if your goal is to put everyone selling physical books out
of a job," he said. Kessel's role up until then had been assuaging book
publishers so that they'd feel comfortable selling their used books on
Amazon."
-- source: http://www.inc.com/krasny/jeff-bezos-recipe-for-disruption.html
Spyware toolbar acquired: https://en.wikipedia.org/wiki/Alexa_Toolbar
Also Amazon has been pushing hard to force them out of the market by having
people send to them (and only them), new releases, exclusive products, etc.
http://www.pcmag.com/article2/0,2817,2415678,00.asp
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So that being said, I found a few alternatives during my search -
There are a few places you can purchase books for bitcoin directly without
using Amazon, and there are also local bookstores (though they are becoming
more consolidated as well - e.g. Barnes&Noble). You'll want to make sure they
are not giving into Amazon, ask them. You can also search Amazon and try to
contact a seller (ensure they are not an Fulfilled-by-Amazon seller, since
this simply means you're still buying from Amazon directly.). Explain to them
that you are looking for store discounts and would like to purchase and have
your product shipped directly to help their small business. I've seen several
companies willing to do this, and sometimes you get a better deal as well.
There are also places where you can swap and trade books. This is probably
the most ethical solution currently. You can use Reddit for example:
https://pay.reddit.com/r/bookexchange