It refers to an advertiser who is a player in affiliate marketing business.

Affiliate merchant is the one who implements systems that enables sales tracking procedures. The merchant provides you with ways to attract affiliates, linking methods, increasing results, monitoring results, paying affiliates and so on. Most of these functions can be outsourced too. There is a way wherein affiliate merchants can track their programs in house. They can either use an affiliate network run by 3rd party or a software program. That’s not all; even the day-to-day activities can either be done from the house or can be outsourced. Thus there exists flexibility in their operation that enables them to go about their programs in a way they want to.