From simple banners to search forms that you include on your pages. Some programs allow you to link direct to specific products or categories of products. This is much more effective than just linking to their home page. Site Cloning A surprising number of merchants will give you a free web site to refer too. Often it will contain an element of co-branding such as your logo or site name.
Commissions vary and are based on either a percentage of the sale price or a flat fee.