Return days are the number of days an affiliate can earn commission on a sale or lead from a customer relationship that originated on their site. Beginning affiliate or publishing sites may feel that people will either click through and buy or not, but many people do not. These are considered purchases, made after comparison shopping and thought or discussion by the buyer. A shopper may click through and buy a book or toner for their printer, but will be likely to do some price and feature comparisons if buying, for instance, a patio heater.

The merchant or advertiser recognizes this and in their programs will set a duration of the cookies placed on the shoppers computer that will tell them the buyer was referred from your site. For example, this is referred to as 7 return days or 45 return days. This identification is customarily linked to the buyer, regardless of whether they ultimately buy by visiting the affiliate site or go directly to the merchant site. In the situation where a buyer has visited more than one affiliate site prior to buying, some merchants credit the last affiliate visited, and others credit the first.

Merchants generally set their return days based upon the complexity of the purchase decision. Affiliates should look for merchants that have generous return cookie durations in order to maximize their commissions. In the situation of a negotiated agreement, affiliates may have to educate merchants, and should be careful not to negotiate away their return days on complex products and services. When theyre set correctly everybody wins.