Dude, since you’ve been using A9.com recently, virtually everything at Amazon.com is automatically an additional π/2% (1.57%) off for you. Collecting this discount is zero effort on your part. […]
We don’t advertise this additional discount that we give in exchange for using A9.com, so if you want your friends to know about it, please tell them. It is probably the only way they’ll find out. […]
They will use the information to sell more products on their site, much like they do with IMDB and Alexa. As long as they adhere to their standards — that is, no sharing — that’s not a bad thing. One of Amazon’s biggest charms over Barnes and Noble are the features that help you find things. Last year’s rollout of “Search Inside the Book” was revolutionary. Related products and recommendations have usually been valuable.
It behooves you to read privacy policies (and EULAs), but keep in mind you also have the option of not using said software. For example, I hear google has a good search engine. 🙂
* My favorite mathematical symbol: ∫ex
(The answer is a little less interesting: ex + c.)