Do I have to add each website I use on CJ.com?



it's not necessary...you can have all the ads be listed for a certain website, and just use the sid info to do the actual tracking (or let yourself know which site the sale actually came from)
 
No, but I highly recommend it for tracking and reports. Especially if you have a few similar websites that are promoting slightly similar products.

It takes 4 seconds to add a new domain to the list and they don't need to be approved. Just go to accounts and do it.
 
Like Berto said, it's good for tracking purposes.

Also, some of the affiliate program managers for the various advertisers on CJ will look at the websites you have listed when deciding whether or not to approve you.

One reason not to list all of your sites: If you don't want the advertiser to know your landing page or website. For CJ advertisers, however, my guess is that this only becomes relevant if you're doing really significant volume.
 
When I was using CJ I would always make sure I had a revelent web site to what I wanted to promote so I got approved. After awhile when I was doing more volume on that network I was getting approved no problem without having a site that fits the product or service.