When we talk about affiliate marketing the Clickbank is great affiliate network to join. The site is well respected and people really buy Clickbank products; and it is secured for online paying and actually (I notice that they offer 60 day money back guarantee for all customers).
This is truly great opportunity for anyone to promote these products and earn money when we look from the perspective of long term benefits.
In advanced search section of the site and under the marketplace category, you can research products and gain insights about popularity of product and how often people buy specific digital or info product. Then you can choose to promote popular products and increase your conversion rate.
Also find out more about advanced Clickbank products promotion strategies http://hubpages.com/business/TheClickbankCodetoLea...