So how do affiliate networks know when a visitor clicks from an affiliate to the merchant site? In most cases, the answer is that the visitor doesn't actually go directly to the merchant site, but instead to a page on the affiliate network site. The URL for the page contains several pieces of information, including:
- an identification number for the affiliate
- an identification number for the merchant
- the URL of the merchant site
When you click on the link, the network site records a hit on that particular URL, which tells them what affiliate sent a visitor to that merchant. It then immediately sends the visitor to the actual merchant site. This happens so quickly that you never see any hint of the network in your browser window. But if you move your pointer over a merchant link on an affiliate site you will notice that the first part of the URL your browser displays is for the network site and not for the merchant.
The network tracks sales using Internet cookies containing these same identification numbers, so they know what affiliate referred the customer to the merchant.