I chose to re-post this from a comments thread that exist in the Google Affiliate Network Blog so that I would not have to search for it if I ever had to. The source comes directly from one of the support members involved in the GAN blog: Bare in mind that these methods that I'm about paste onto this post could change due to the constant upgrades and improvements that GAN is going through. The date and time that these methods were given out was on July 15, 2008 8:32 AM by Google Affiliate Network Marketing.
Google Affiliate Network publishers can use as many sites as they like. However, ConnectCommerce only allows one site to be associated to each account.
You have three options to use multiple sites in Google Affiliate Network:
1) Create separate Google Affiliate Network accounts for each site you want to have advertiser links on. You will have to submit separate applications for each site you want a Google Affiliate Network account opened for.
2) Use member identification (MID) tracking.
MID tracking is a system where you give certain links separate codes so you can tell which site the click came from. MID tracking is necessary if you wish to keep track of commissions made from each site separately.
To utilize MID tracking, append your standard Google Affiliate Network tracking link with an additional URL parameter beginning with the characters mid=
For example, a standard Google Affiliate Network tracking link looks like:
where lid is the unique ID of the link assigned to you by Google Affiliate Network, and pubid is the unique number that identifies each affiliate publisher.
To use MID tracking, add the MID parameter (&mid=) to the end of the link, such as:
where xxx = a unique identifier that corresponds to the website that you need to track separately. MID’s can be up to 256 characters long, and all special characters must be HTML encoded.
Publishers should not be passing any personally identifiable information (such as email address, social security number, banking information, etc.) in the MID field. If this is done, Google Affiliate Network will purge the information from our system and it will not be recoverable.
3) Use one Google Affiliate Network account. You would use the same link on all sites and track all activity in aggregate.
If you are going to use option 2 or 3, please also make sure to list all of the sites that are associated with your account in the "Publisher Site Description" section of your account profile in ConnectCommerce.