The truth is the visitor or clicker will eventually find out that they’ve been referred to the affiliate merchant by you from the ultimate landing URL — sometimes this may be totally redirected to the clean home page of the merchant, but many’s the time it’s not.
So the one thing you can make sure is the reader of your site must click through your affiliate link to get to the merchant. And the following snippet will help you achieve this. Start a index.php file and put this in:
<?php header("Location: http://www.example.com/referral.php?aff=12345"); ?>
In which http://www.example.com/referral.php?aff=12345 is your referral link. Save this file somewhere in your domain such as /go/example. The next time you want hide and cloak the real affiliate URL, or at least make it look more neat, just point your readers to /go/example and they will be automatically redirected to the affiliate link.