You can setup your affiliate program where you fully manage it (internal), or have a third party network manage it for you (external).  There are pros and cons for each method. 

Internal affiliate programs "may" give you more control over your program, you create your affiliate contract and word it the way you feel is most appropriate.  It can also be cheaper to setup and there are no commissions paid to a third party which can be as little as 10% of the commissions paid or as high as 35% depending on the program and the managing third party.  Some external programs will require a setup fee and which can be anywhere from $500 to a few thousand dollars! 

External programs offer you a lot of services and will give you instant exposure to their network of members.   Additionally, many people feel that having a third party involved will offer more objective monitoring and give them additional confidence that they will be paid.   Often times, such affiliate networks have user friendly interfaces and professional reporting systems that are useful to both the merchant and the affiliate.

Affiliate Networks

The two largest affiliate networks are Link Share and Commission Junction.  Link Share costs thousands of dollars and is used by the large corporations.  Commission Junction is next in expense and will cost you over $1000 for setup fees, and now includes a $250 monthly minimum.  They have a huge member base and will market your program to that base.  We still find the price/benefit ratio lacking but we wanted to point out the reason why you are paying the setup fee.  Click Here to see how to integrate CJ code into Miva Merchant.  ClickTrade of Microsoft was a great alternative since it had no setup fees and did have a huge member base, but it ceased operations September 6th 2001. 

We have researched alternatives to ClickTrade and found ClixGalore to be an even better substitute with no setup fee and reasonable escrow amount.  Their interface is excellent, and we have setup all our customers with their program after ClickTrade ceased operations. We tested their system in a multitude of ways before we recommended them, including customer support and found that they respond to e-mails and calls.  Click Here to see how to integrate ClixGalore's code into Miva Merchant. (we have an affiliate relationship with ClixGalore; Click to check our disclaimers and arbitration policy).  Another alternative is Lead Hound (no affiliation) with no setup fees and reasonable terms.   They also respond well to inquiries and would have been our choice had we not gone with ClixGalore.

Internal Affiliate Programs

Miva Merchant 4.x comes with a built-in "basic" affiliate program.  Previous versions do not.  While Miva has fixed some bugs in the latest update 4.12, we do not feel comfortable at this point to recommend it as a perfect choice as an internal affiliate program.  The interface that your affiliate uses is limited in terms of reports, and the commission accrual has not been fully tested to ensure full accountability.

There is a third party module that offers a very professional package at a reasonable price.  You can check it out at Viking Coders, one of the top module makers in the Miva community.  In addition to offering the affiliate tracking that one would expect, it offers you the ability to have a different look and feel to your store based on what affiliate link the customer came from, and it even allows you to have the product price change accordingly.