You have three options to use multiple sites in Google Affiliate Network:

1) Create separate Google Affiliate Network accounts for each site on which you want to have advertiser links displayed. 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: http://clickserve.cc-dt.com/link/tplclick?lid=41000000010825647&pubid=21000000000000054 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:http://clickserve.cc-dt.com/link/tplclick?lid=41000000010825647&pubid=21000000000000054&mid=xxx 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. Also, if you use option 2 or 3, once you have decided on an advertiser that you would like to join, log into your Google Affiliate Network account and change the URL that is listed to one you would like the advertiser to see, in order increase your chances of being approved. You can do this by going to Settings (in the top right hand corner) and then clicking Account Profile. After you have been approved, you can go back to your account profile and change the URL back to your main site. Repeat this process for as many advertiser programs/multiple websites you own.