Instead of having an exposed affiliate link, it's better to hide it inside a redirect. It hides the referring URL from the merchant. It also hides your unique affiliate ID from people trying to spy on your campaigns.
Not all WADS allow redirects, so be sure to check their policies. Some, notably the search engines, want the destination URL to be a landing page. Once the prospect is on the landing page though, you can add redirects, click tracking and retargeting cookies.
If you're using a click tracking service like Voluum or TrackingDesk, they create the redirects for you. You'll need to refer to their instructions and videos on how to set them up.
If you're not using a click tracking service, here's how to set redirects up on your own Unix server using something called .htaccess. It's nothing more than a simple text file.
If you have a Unix server, it may already have an .htaccess text file on it. You can add the redirects to this existing file, after any other text that may be present. (Just make a backup of it before you modify it.)
If do not see an .htaccess file on your server, you can create one in a plain text editor like BBEdit, TextWrangler, NotePad, etc. Each redirect needs to be on its own line and typed out exactly as shown in the examples below.
Redirect /aws http://www.aweber.com/?19118
Redirect /dmc http://www.dynamicmedia.com
Redirect /ims http://www.internetmarketingsecrets.com
Type the word Redirect, followed by a space, then a slash, followed by any code you make up, then a space, followed by the affiliate link. In the examples above, I made up the codes 'aws, dmc, ims' so that they are easy to remember.
Once you have all the redirects typed out, save the page to your computer as htaccess. Then upload it via FTP to the root directory of your Unix server. Now add the period in front of the filename so it looks like this .htaccess. That's all there is to it.
If you can't see it after uploading it via FTP, make sure you have "show invisible files" selected. Then refresh your FTP software and you should see it.
So now the links leaving my ad or landing page look like this:
When someone clicks that AWS link, their browser goes to my redirect server, where it reads the .htaccess file, then gets redirected to the affiliate program.
In addition to cloaking affiliate links, the real power of the redirect is being able to change links on a global level. For example, if an affiliate program goes down or gets moved, I don't have to change hundreds of links, in dozens of ads and landing pages. All I need to do is change the one affiliate link inside the .htaccess file and all the links are updated.
As a final step, I add a little blurb as a home page on my redirect server. It helps explain why merchants are seeing my domain name in their referrer logs.
ThisHereWebsite.com is click tracking server operated by Cyber Age Media Ltd. We are a digital advertising agency located in Vancouver Canada, which is why you are seeing referrals from us in your server logs.
We provide our clients with media buys, account management, design and creatives for advertising campaigns. In sum, we create persuasive ads that get clicked, generating qualified leads for our clients. Click here to learn more. <— Which is a link to our agency's website.
A good advertisement is one which sells the product without drawing attention to itself.