What are the pros and cons in choosing what products to promote on your affiliate site? Digital goods or physical goods? Digital goods being software, e-books or subscriptions vs. physical goods such as books, electronics or clothes? Or do you simply focus on the "other" criteria such as payout, competition and vendor site quality?
It will completely depend on your target market. What does your target market need/want? Is the digital good priced right? Does it need to be a physical to demand the cost? Lots of factors will go into your decision. But you can always do one thing that works everytime... test it
Google for Affiliate Masters Course. It's a good free ebook that can answer almost all your affiliate related questions and a bit more.
I actually read that ebook from start to finish. Took a while though, it has over 200 pages. If you're new to affiliate marketing, it's a great value for the investment (a few minutes to find it and download). It's also been updated for 2005, so it's worth a look.