Originally Posted by Nathan

The legitimate reasons are when for example there is a link to more than one site on a gallery, the code needs to be changed for at least one of them... Or, for example eurorevenue changes them to allow for better customized join pages, because options can easily be targeted to programs, and they display different options on the join pages depending on the country you are from, you get credit for all sales, but they are tracked in seperate programs all paying the same amount.

There are a lot of other things you can do with NATS which would require you to do something like this.

Hope this answers your question