Years ago Affiliates would try to optimize sites for keywords and funnel their traffic to Merchants. PPC Affiliates would drive customers, at their own expense, to a merchant's site and the whole focus was to drive sales. The old belief was that Affiliate's needed the Merchants and that the Merchant's held all of the power. After the Affiliate industry has begun to mature, Affiliate sites have began to mature as well and the tables turned to where Merchant's are now the ones who need to rely on value adding Affiliates. The issue with the old Affiliate model is that the model was focused on the Merchant instead of the Affiliate's long term success. Today's Affiliate models have turned Affiliate sites into destinations on the web, which the Merchant's have to access if they want the value-add. Affiliate's have built empires on their destination sites and what you should be asking yourself is, "Have I done the same?". Think about it, what have you done to keep and maintain a fan base?
Newsletters
Does your site have one? Your newsletter is ike your ATM machine or a large bank account that gets interest. If you don't abuse it, then you'll almost always get opens and sales just like there will be money to withdraw. That newsletter is something that you can rely on for traffic and sales and loyalty. It doesn't matter what or who the Merchant is. If your marketing is done well, your newsletter will make you money and Merchants will give bonuses and higher commissions for this type of exposure. You can also sell ad space in your newsletters and monetize it multiple ways.
PPC
If you're driving your PPC traffic directly to a Merchant's site, you might get better conversion rates, but you've lost a customer for life. If you create a landing page or website which compares prices, if it is user friendly, has a newsletter sign up, social media share buttons, etc... you have created something that people will be able to come back to and remember (If your domain name is memorable and brandable). Ask yourself, why am I paying to send a Merchant traffic directly when I can send it to my own site, build my own brand and my own user base that I can market to again and again? Doesn't make much sense now, does it?
Domain Names
If you only buy domain names because of keywords, you are missing out. A domain name that has 5 keywords in a row -- even worse; with dashes - isn't easy to remember. Instead find a domain name that makes sense for your site's purpose and that is fun to say, easy to type and even easier to remember. If your url is focused on keyword matches for the search engines, you may stop people from coming back again. If your url is easy to remember or brandable, you may have to work harder at SEO, but you are building a site with repeat visitors and a better chance for long term and more success.
Years ago Affiliates built sites to drive traffic to Merchants. Now Affiliates are building sites to create their own online destinations. By creating a place for people to remember, come back to and recommend, you can build a site that you can rely and depend on for income. Now ask yourself, are you focused on matching keywords for Google or are you building yourself a brand? I'd like to dedicate this post to Scott Campbell @Scotch who passed away yesterday. He was one of the top Affiliates in the USA and one of the smartest and best people in the industry.