Let's extend this a bit, what other similar sites do you use and why?
Thanks, rep will still be added.
As what's been pointed out already, Clickbank is more for digital download type products.
CJ has a lot of merchants you'll see at your local mall, merchants you've heard of before.
Computers, they have Dell, Apple, HP.
Clothing, they have Gap, Old Navy, Jockey, Chadwicks, Pacsun etc.
CJ is a traditional affiliate network. They have merchants with products, with datafeeds.
Other popular affiliate networks like CJ are:
Linkshare
Google Affiliate Network aka GAN
Shareasale
Pepperjam
Sign up to those networks and you'll find more of the type of merchants I mentioned above.
There is another category that gets lumped into those traditional affiliate called CPA networks. Networks like Copeac, Clickbooth, aZoogleAds, etc. One of the major differences you'll find is those CPA networks generally don't have product links like the traditional affiliate networks do. They do more lead type stuff, whereas traditional networks do more per sale type stuff, they do leads as well but mainly per sale. Another difference you'll generally find is on traditional affiliate networks like CJ, the merchant programs are run by affiliate managers, OPM (outsourced program manager) or somebody else from the company themselves, not the network* On CPA networks, it's usually the merchant has an offer, gives it to the network and you work with a network representative, a merchant has less control on who gets to promote those offers.
*there are occasions where somebody from the network runs the program, it's a service some of them provide nowadays.