I have gained enough insight in the last one year by going through a few forums and reading about people’s experience and numbers that made me realize a few things. They are
* The same website can’t do well in both Google AdSense and Affiliate programs. Typically, it’s one or the other.
* However, usually CPC advertising beats the CPA affiliate income by a wide margin.
* Good pagerank doesn’t always translate into a good traffic. There are websites I know that have just a PR 4 but get as many as 100K views a month! And then there are PR 6 websites that would be glad to get more than 3K a month.
So, there is really no single source to optimize your website revenue. It depends on the characteristics of the website. If you have a high PR but low traffic website, then you are better off participating in link selling/buying program than in Google AdSense since it pays you more. For example, if you have a PR6 website with about 100 views/day (3K visits per month). Say you get a CTR (click-through-rate) of 3% (which is quite high actually). It converts to 90 clicks a month. Say the CPC is $0.25 (which is also reasonably high these days). It translates to $22.50 a month. However, if you participate in link selling/buying program, you can easily get $25 per link (at 50% commission) and with 4 links, you get $100.00 a month! So, why would you go for advertising when you can get more money by placing links?
Yes, I know selling/buying links is not liked by search engines, more with Google. But then, it’s all about supply vs demand. Isn’t it? Why else, would people want to bid for keywords instead of expecting Google to charge flat fee with round-robin slots? Similarly, there are some companies who are willing to spend extra money to improve both their page rank and also their website visibility as widely as possible. For example, what has kosmix.com anything to do with daily.stanford.edu? Or with www.arabicnews.com?