Earn Automatic Amazon.com Discount by Using A9 Search Engine

A few weeks ago, Wisblawg reported on a new personalized search engine called A9 which is powered by Google.
Just in time for the holidays, I’ve just confirmed that A9 is offering select users an automatic 1.5% discount on purchases made at Amazon.com. When I clicked on the A9 Instant Reward Active link in the Ready to Buy button on Amazon, I was presented with the following details:

(User name), 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. It will be applied automatically at checkout (it will happen whether you use the shopping cart or our 1-Click Shopping®). You don’t need to do anything to get this discount except keep using A9.com as your regular search engine.
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. All they have to do is use A9.com as their regular search engine. They should make sure they are signed in to A9.com (it should be recognizing them by name) so that we can be certain they get credit for their visit.
While the π/2% discount is a good additional reason to use A9.com it isn’t the best reason. A9.com licenses its web search results from the industry leader Google, and then supplements those results with Amazon’s Search Inside the Book™ results. The coolest feature is that A9.com keeps track of your search history for you on the server side. To see how this works, do some A9 searches from your computer at work and then sign in to A9.com from your computer at home.