I currently own 160 domain names. These domains are used for a variety of things, including my websites, blogs, and affiliate products. Many people mistakenly believe that forwarding a domain name to an affiliate link is all they need to do. To make the entire process complete, you must also mask your domain. This is done so that no one will see the affiliate link you are sending them to.
For example, I promote several products on Clickbank to make some passive income each month. I both forward AND mask one of my domain names to each affiliate product I promote. That way I am able to direct people quickly and easily to where they may purchase a product that will be helpful to them, and the domain names are musch easier to remember than a long affiliate link. It is much easier to promote something like PublicDomainContentNow.com (this is an incredible product, by the way, and is not from Clickbank) than it is to give out an affiliate link that is twice that long and contains special characters like questions marks. Also, if you are writing articles to promote affiliate products, programs, and services you must use a domain name, because the article directories will not allow it any other way.