Amazon is the on-line shopping portal, Which has more than 6 crore products to promote & earn commissions.
It works the same way, as the other affiliate programs. Only difference is that you are called an associate rather than an affiliate.
The commission varies from 4% to 12% Depending on the products. There are many ways to promote their products.
You can have a web site with amazon products,
You can also promote through Face Book Group, exclusively For the Amazon Deals & Offers.
You Can use mail marketing.
You can use blogs to write reviews, with a link to the product.
You can use "Associate Stripe", in the associate central page to share the product links that you wish to promote in social media - Face Book & Twitter.
You Can also generate short links, image links right from your associate page.
Now We also can promote Global Products, through their International Stores.[it is a recent add on in India now].
It is a no cost program and you can join free.