Affiliate Managers and other web marketers have employed a variety of tracking technologies and strategies, over the last few years, in their quest for accurately accounting for referred customers. Tracking customers "from click through to sale" can be accomplished with various tracking methods, such as:

• Simple Direct URL Links CGI/URL Tracking Cookie Tracking Self Replicated Pages Sub Domain Tracking
• Database Record Match Tracking

As you'll read in the next few paragraphs, each of these methods has strengths, and each has weaknesses. However, you'll see that Cookie Tracking is the clear winner as the preferred single tracking method when it comes to reliable, flexible, and convenient tracking. When exploring the different tracking methods, an affiliate manager must consider:

• How flexible is the method? (Can I track everything that I want to track and will it work with my shopping cart or ordering system?) How easy is the tracking method to administer? (Must I exert much effort re-designing and maintaining my website to work with the tracking method)? How reliable is the tracking method? How easily can an affiliate defeat the tracking method?
• Does this tracking method affect the performance of my website or web server?

Simple Direct URL Links

A Simple, Direct URL Link is the most basic, and most limited form of referral tracking technology. The affiliate ID is visible to the customer in the URL with this method, because it passes the referring affiliate's ID directly to the URL of a specific page (which must be equipped with an order form). This specific page is coded with a script, which reads the referring affiliate's ID in the URL, and passes it into a "hidden field" in the order form on the page or to a visible "reference number", that can be printed or reported by the customer. While this simple method sufficiently tracks immediate sales on a single-page sales site, it cannot track the affiliate ID if the customer leaves this page and returns later. Since the affiliate ID is visible in the URL, customers can easily defeat the tracking by simply removing the affiliate ID from the URL.

CGI/URL Tracking

CGI/URL Tracking is a relatively effective, yet clumsy, tracking method that passes the affiliate ID throughout the merchant's entire website. The affiliate ID is visible in the URL in this method, too, and "follows" the visitor until she reaches the ordering system, where the ID is detected from the URL string. "Following" the customer throughout the site is accomplished, in most cases, by processing all internal site links through a Perl script or JavaScript which:

1. reads the current URL grabs the affiliate ID
2. appends it to the URL of the next page.

This method, though fairly effective, is a bit fragile and cumbersome, as it requires careful design of the website and maintenance of every link within the merchant's site. Moreover, under heavy traffic, the script can become a "bottleneck" to the merchant's web site. Furthermore, if the script ever fails, the merchant's site will fail. The CGI/URL Tracking method is usually used in conjunction with "cookie tracking". This combination allows for the tracking of customers who have disabled their cookies. CGI/URL Tracking, however, is losing its popularity as a backup mechanism because in most circumstances, Internet users who are security-conscious enough to disable cookies, are also savvy enough to circumvent the CGI/URL method. Customers can easily disable the tracking by simply removing the affiliate ID from the URL and re-entering the site.

Cookie Tracking

Cookie Tracking is the most popular method to track customers "from click through to order", because it is simple to implement & use, requires no significant web design considerations, nor does it impact the performance of the web site or web server. This method works by writing a small text file, a "cookie", to a user's browser when they click on an affiliate link. This cookie holds the referring affiliate's ID, which can be identified at the merchant's order page to credit affiliates for referred sales.Cookies make tracking affiliate-referred-sales very convenient. The cookie can be read and used on any page or on any form, and can be used in conjunction with almost any ordering system. Plus, the cookie that records the affiliate's ID can "live" for as long as the merchant desires, allowing affiliates to get credit for customers who clicked on a link weeks, or months, before finally purchasing or making a repeat purchase.Cookie Tracking is essentially invisible to the user, because cookies are written and read "behind the scenes". Unlike the other methods, the merchant's URL does not need to display the affiliate ID. The only drawback with cookies, is that a small number of web users intentionally "disable" cookies, and therefore, they cannot be tracked. The number of Cookie Enabled browsers is growing, because a majority of web surfers' favorite sites require cookie use; plus, the option to disable cookies is not obvious in the two major browsers. Those users who take the trouble to disable cookies are, oftentimes, the same users who will probably be wary of other tracking methods and have learned to intentionally bypass those as well.

Self Replicated Pages

Self Replicated Pages (or SRP's for short), offer affiliates a template based web page, or multiple web pages, that is found in their own directory at the merchant's website. SRP's are an effective and reliable form of affiliate tracking, but their use requires careful planning, the creation of template web pages, and ongoing maintenance.With SRP's, the affiliate receives one or more pages at the merchant's website, exclusively used for that affiliate's referred web visitors. Since the affiliate's website is designated by a directory name, the affiliate's ID is found within the URL. As a result, customers who do not wish to be tracked can defeat this tracking method by removing the affiliate directory from the URL, and re-entering the site.For maximum benefit, SRP's are oftentimes used in conjunction with cookie tracking: the SRP provides the affiliate with a URL to which he can point his customers, and the cookie tracking takes over from there.

Sub Domain Tracking

Sub Domain Tracking is very similar to Self Replicated Pages, in that it provides an affiliate with a full URL to which the affiliate can direct customers. Unlike Self Replicated Pages, though, this method gives affiliates an actual sub domain at the merchant's site, not a simple directory path found at the merchant's main domain. Sub Domain process is one of the more administratively demanding tracking methods. The process requires that:

• DNS is configured to point this new sub domain to the appropriate web services on the web server web services are created for this new sub domain
• the web services point to the appropriate files for viewing by web surfers to the sub domain. The web files must either be created (just like SRP's), or the web service must point to a predefined root directory.

When merchants employ this tracking method, customers are able to see some form of affiliate identification, because the affiliate ID is shown in the URL as the sub domain. Although customers can see this identification in the URL, since the sub domain is part of the URL, attempts to defeat the system by removing the sub domain from the URL and entering the site with no sub domain is less likely than with other URL Visible affiliate tracking methods.The Sub Domain Tracking method is relatively server intensive, since web services must be created for each and every sub domain used, and it may require additional hard drive space to be wasted. The website may need extensive re-design and maintenance to handle sub domain tracking. Furthermore, this method requires the intervention of a web server and DNS administrator, or expensive scripting that can automate the process.When considering the use of this method, affiliate managers must carefully plan the ordering system and its integration with the sub domain option, and cookie tracking should be used as a backup.

Database Record Matching

Database record matching (also called "lifetime affiliate tracking") is the least used of the methods because it is difficult to operate and maintain, and must be used in conjunction with at least one of the other tracking methods; it cannot be used alone. Database Record Matching rewards affiliates for returning customers, not new customers. The initial sale must employ some other form of referral tracking, and then store unique contact information about each customer (their email address, name and address, credit card number, etc), along with the referring affiliate's ID. When that customer returns and buys again in the future, the customer database can be searched to find that the customer is "owned" by an affiliate. This affiliate will receive commissions on that customer's repeat purchases for the life of the system

Todd Farmer & Jeff Doak
Kowabunga Technologies
Producers of 'My Affiliate Program'
The Premiere WebBased Affiliate Tracking, Management & Automation Software