In the last several years merchants have become savvy about search engine optimization (SEO). A site's rank in the search engines -- for a small company site, at least -- can be significantly elevated by obtaining more incoming links to the website. An affiliate program is an effective way to do this -- but only if the affiliate links themselves actually point to your domain.

Responses of Affiliate Management Software Types

When I published the first edition of the Report on Affiliate Management Software in 2001, it was simpler. Licensed affiliate management software on your server or custom-programmed systems had affiliate URLs pointing to the merchant's primary domain. Network and hosted ASP sites did not (with very few exceptions). These days the picture is dramatically different. Now, nearly all affiliate software programs provide a way for the affiliate links to point to merchant's site -- so long as the merchant insists. Here's the picture:

1. Licensed and custom affiliate management software on your own server always has affiliate links that points to your domain.
    
2. Hosted ASP software uses one of two approaches to have affiliate links pointed to the merchant's domain.
    
   • Redirect script. A small script installed on the merchant's site detects affiliate click-throughs to the domain name, then redirects those click-throughs to the affiliate software vendor's server. Here a cookie from the vendor's domain is placed on the visitor's browser and the visitor is finally redirected to a landing or product page on the merchant's domain. Complicated, but all this happens quite invisibly.
      
   • JavaScript. A small script installed on the merchant's site detects affiliate link click-throughs and resulting sales, and communicates this information to the hosted ASP server where it is recorded. Affiliate cookies are placed on the visitor's browser from the merchant's domain, not the vendor's domain. Examples here are AffiliateClicks and MyAP. This is better than the redirect approach for reasons I'll explain below.
      
3. Some hosted ASP and network vendors don't generate affiliate links directed toward the merchant's domain. This could be for one of several reasons: (1) their merchant clients are so large and well-branded that they don't need increased search engine ranking, (2) the smaller merchants are ill-advised by the vendor, (3) the vendor just hasn't bothered to offer this feature, or (4) the vendor is trying to protect the merchant's affiliate program from highjacking (which I'll explain below).

Clean Links

There isn't full agreement that "clean" affiliate links to an merchant's domain (that is, without question marks, without query strings, and without a cgi-bin in the path) are more search engine friendly than others. A couple of vendors brag on their clean links. But at some point clean links lose functionality. The link usually needs to communicate at least two elements besides the domain name -- (1) the unique affiliate ID, (2) the target landing page on the merchant's site, and sometimes (3) the particular ad used.

Link Popularity Bump

However, there's another side of this issue. I spoke with Steve Messer, CEO and founder of LinkShare. He contends, "Many merchants are under a mistaken belief that [affiliate links to their domain] will improve their link popularity in search engines." LinkShare has done tests, he says, that show little positive search engine ranking bump from affiliate links. I wonder, however, if this is true of all websites? Small online stores with little brand recognition may get a large relative rank increase from affiliate links, whereas a larger, well-branded store (typical of LinkShare's clients) may not notice much rank increase at all since they already have many links pointing to their website.

Stealing Your Super Affiliates

But Messer makes some good points about links pointing to the merchant's domain that larger companies should take quite seriously. "Using a merchant's domain name in the affiliate link," he says, "completely exposes a merchant's affiliates to its competitors. It's too easy to look up a merchant's domain in any search engine, find all affiliate sites linking to that merchant, and then perform a cross reference with a site like Alexa to identify all the high traffic driving affiliates." Then the competitor could contact those super affiliates and win them over to the competitor.

Spyware, Adware, and Anti-Spyware

Additionally, spyware and adware applications are designed specifically to identify  affiliate links, particularly those of larger merchants, often using those links to trigger their programs that pop up an ad for a competitor on the infected computer.

A further problem results when anti-spyware programs are set to block domain names of "evil" ad programs. Some are blocking the domains of legitimate companies like LinkShare and Commission Junction. Commission Junction responds by changing the domains of its affiliate links often in order to stay ahead of anti-spyware updates. Since computers running anti-spyware programs can't set or read cookies for these blocked domains, many affiliate commissions are being blocked. (Anti-spyware programs, however, don't as a rule block merchant domain names from setting cookies.) While merchants may save money not having to pay these commissions, wise merchants know that high-performing affiliates who aren't paid adequately will go elsewhere. Do you know whether your affiliate program vendor's domain name is being blocked from setting and reading cookies by anti-spyware programs?

Encrypted Links

"LinkShare links are designed to be encrypted," says Messer, "in order to protect our clients from all of the above without negatively impacting popularity. LinkShare will soon enhance this feature by upgrading to a new encryption scheme that will be more effective in our continued battle against spyware/adware."

Messer concludes, "Using affiliate links with the merchant's domain may achieve some minimal gain today, but LinkShare believes that this short term benefit weighed against the risk of exposing the network to competitors and spyware is not a good trade -- off for any merchant or affiliate."

The Bottom Line for Merchants