The wordpress call to action plugin will let you include dynamic discounts with a call to action for your visitors which will boost your click through rate and the number of sales you make.
Take a look at the sample post here for more information; http://www.electrictoothbrushpro.com/oral-b-electric-toothbrush/
The only things you must have in order to use this is a wordpress blog and an amazon associates account. Both are free so there is no reason why you cant start earning money with this plugin right now.
Here is what it looks like in action
First of all a loading screen is shown to get the visitors attention
Next, this changes into an offer with a big discount which means the user wants to click on it for find out more