The most widespread way of promoting goods is placing Google AdWords ads with links to affiliate webstores. You may use social networks (Facebook, Twitter, Google+, YouTube, LinkedIn, Instagram, etc), blogs and forums, you may use SEO strategies. If you want to know exactly what strategies work and what fail, you need to test, track and measure everything you do. Use Google Analytics (which is much better than any basic stats most affiliate programs provide) and other statistic services. Join Amazon Affiliate.club to learn how to promote your affiliate store succesfully. This club helped me greatly!