Affiliate marketing has grown quickly since its inception. The e-commerce website, viewed as a marketing toy in the early days of the Internet, became an integrated part of the overall business plan and in some cases grew to a bigger business than the existing offline business. According to one report, the total sales amount generated through affiliate networks in 2006 was £2.16 billion in the United Kingdom alone. The estimates were £1.35 billion in sales in 2005. MarketingSherpa's research team estimated that, in 2006, affiliates worldwide earned US$6.5 billion in bounty and commissions from a variety of sources in retail, personal finance, gaming and gambling, travel, telecom, education, publishing, and forms of lead generation other than contextual advertising programs.
Do they value and help their affiliates? Some affiliate programs do an exceptional job of communicating with their affiliates, notifying them of upcoming sales, offering marketing advice or tools, offering contents and prizes during promotions and more. These types of affiliate programs are a pleasure to be a part of. Ultimate Bundles is an excellent example.
I personally prefer to do it that way--you can create a more convincing review that's more likely to make sales. It's not always possible or practical, though; for example, would you break up with your significant other just to test a product for getting your ex back? ;-) In cases like that, or if the product is expensive, it's usually best just to use the vendor's affiliate resources instead.
I, too, have always looked at ClickBank as a secondary and even tertiary monetization source. But it can be a great sources of revenue. I linked one of my articles to a related product on CB, and without really doing promotion or anything unusual, I get a few sales a week. Mind you, the keyword(s) for the post aren't that huge either. So, even though the traffic not huge on that post, it still manages to get some sales.