The highlight of affiliate marketing is the symbiotic relationship that exists between merchants and affiliates.

Every time a selected merchant sells one of their products by your reference, you, as the affiliate, receive a commission for originating that sale.

But how do merchants know whether a product sale was referred by you, or by another affiliate? How do they track their sales to compensate the right associate?

Individual merchants and affiliate programs use special software to keep track of sales. Whether it’s an out-of-the-box application, or a more advanced alternative, all affiliate software uses cookies to determine the origin of a purchase.

What Are Cookies? How Can They Help Me Make More Sales?

Simply put, a cookie is a data bit that is stored in a user’s computer memory to keep tabs of the user’s browsing history and preferences. The cookie’s data contains information such as the link that originated an affiliate purchase, and the affiliate ID of the referral.

As an affiliate, you should pay special attention to the cookie’s duration, or return day.  Since cookies are set to expire after a given period of time, they bear what is called a return day to determine how long they will be stored in the user’s computer – thus defining how long the user has to complete the sale.

Say you are promoting an affiliate product with 30-day return day cookies. This means that even if a user, after clicking your “hoplink” to access the merchant’s site, doesn’t buy on their first visit, as long as they purchase within those 30 days, you will get a commission.

How Long Can Cookies Last?  Are Lifetime Cookies the Best Option?

While cookie durations vary between merchants, you’ll find that the most common return day denominations are 30, 60 and 90 days.

If you’re looking for a product to sell and come across “lifetime cookies,” don’t be fooled. Even though the general rule for cookies is “the longer, the better,” a lifetime cookie can limit your ability to compete in the affiliate market. Here’s why…

We know that once a user clicks on your ad, as long as you are the first to refer them, you appear as the lead affiliate. And we’ve just established that if a sale occurs within the cookie’s return day period, as a lead affiliate, you get paid.

But what if this is not the case? What if a user clicks on one of your ads to make a purchase in a merchant site, but you weren’t the first affiliate to do the referral?

Then, all your efforts would simply be aiding in other affiliates’ work – earning them money, as opposed to profiting you.  If instead, you promote a product with cookies that expire within 120 days, this will allow you to renew your competitive edge every 120 days – while giving you a long period of time for the consumer to decide on buying your affiliate product.

So, How Do I Find a Cookie’s Duration?

Finding cookies’ length information on merchant websites can be a hassle. To save some time, go directly to the business’ online privacy policy and skim through the disclosure. This will likely indicate the cookie length that the merchant site sets if a visitor comes to them versus clicking an affiliate link.

So in addition to the privacy policy, the affiliate should also check the actual affiliate agreement, which spells out the cookie length set when a visitor clicks on the affiliate link. If the cookie length is not listed there, you can check the cookie information yourself, using your browser’s data. While Internet browser utilities vary, these are the general steps to follow:

1. First, click on the affiliate link that is given to you, so that it’s registered in your PC’s recent memory.
2. Open your browser’s “Cache Folder.”
3. Find a cookie named affiliate/companyname@merchantwebsite.com.
4. Open the cookie’s information (right click). Within the text, you must be able to distinguish: (1) your affiliate ID#, and (2) the cookies’ expiration. If this information is not identifiable, you probably shouldn’t trust the source – move on to the next product.

The method outlined above can also be used to check if merchant sites have fully functional cookies. Basic affiliate software can be inefficient at tracking cookies, so checking cookie functionality beforehand will ensure that you get the credit if you make a sale.