I joined Amazon Associates which provided me with access to their Amazon Central website. The website provides you with several options for creating ads for your blog and a code that makes linking text and images to Amazon.com quick and easy. The only thing that was really frustrating was the requirement to use Amazon Payments.
The interface was pretty simple and they would post various seasonal ads to provide you with lots of options. I used the features in a few of my blogs and set up a small ad in the sidebar. I was already using AdSense and wanted the advertising to blend.
A few months after getting everything set up I received an email from Amazon Associates stating that my affiliate account had been closed due to not having enough referrals. The reality is the blog was in flux from a business only concept to a more my life concept. Either way there wasn't a lot of options in my posts to tie back to Amazon products. I was surprised that they would close the account after a only a few months but it's there program so whatever. I removed the Amazon advertising and deleted the coding for the Amazon Central features. No point in advertising for them for free right?
That was almost 6 months ago. Yesterday I received another email stating that my account was being closed for inactivity. Well of course it was inactive, Amazon closed it 6 months ago. I don't know if Amazon is confused or if their emails are just poorly worded but either way if you are looking for a stable program for affiliate marketing stick with AdSense.