Affiliate marketing has increased in prominence with the internet age. Amazon popularized the practice by creating an affiliate marketing program where websites and bloggers put links to the Amazon page for a product being reviewed or discussed in order to receive advertising fees when a purchase is made. In this sense, affiliate marketing is essentially a pay for performance marketing program where the act of selling a consumer on a product is outsourced across a potentially vast network.
From what I’ve observed, most of the “programs” you’ve listed are networks, and most of them support dozens, hundreds, even thousands of merchants – in a huge variety of niches. Amazon is not technically a network, unless you factor in the presence of about a dozen entities like Zappos, Woot, Endless and the like. With very few exceptions, networks are diversified. Performance-Based.com focuses on eco and green merchants. Some support a particular locale – European merchants, for example.
If you haven’t already, expanding your potential profit by diversifying your affiliate networks is a great way to build in additional revenue streams for your business. Before diving into any one in particular, make sure to do some research on the program or network to confirm its legitimacy, potential for profit, and alignment with the types of products and services highlighted on your website.
CPA marketing programs pay affiliates when a specific action is taken by the referral or lead. Common actions include clicks, impressions, form submits, sign-ups, registrations, or opt-ins. Since Cost-Per-Action models don’t necessarily involve a direct sale (and involve more risk taking) the payout percentages are far smaller than they are in Cost-Per-Sale.
Websites and services based on Web 2.0 concepts—blogging and interactive online communities, for example—have impacted the affiliate marketing world as well. These platforms allow improved communication between merchants and affiliates. Web 2.0 platforms have also opened affiliate marketing channels to personal bloggers, writers, and independent website owners. Contextual ads allow publishers with lower levels of web traffic to place affiliate ads on websites.
However, be aware that you need to submit an application to most of these networks to be accepted. Once you're accepted in, you're often required to apply directly to the merchant afterwards. So there are two layers or gates that you need to bypass. That's also why it's important to build up your platform and create that emotional bridge between yourself and your audience before attempting to promote anything to them.