Affiliates love beneficial
strategies that cost them nothing. After all, why pay when you can use alternative free methods to market your site? The article linked on top, highlights 7 strategies I think. Basic strategies like sharing links, target forums, write good content and such but with further descriptions.
But remember, free can only do so much because it means that you're the onl one doing the work. It's when you can replicate your efforts in others that you really start to tap into the potential of your business.