First of all before I start this post I must say this is totally base on what I have gone through so far and what I have experimented. I have notice even though the Page Views and Website Visits increased income was not increased proportionally. Actually it should not be. Anyway I thought I should have a close look on the behaviour of the visitors. (image from http://www.geeksaresexy.net)
Couple of things I can think of
I have not optimise my AdSense Ad placement
I have not choose the proper colour combination
More than that the blog I was using AdSense ads doesn't seems to attract people who likes or people who will click on Ads. If I make it simple. People who knows the secret behind the Google Ads or any other advertisement will not or hardly click on the Ads as they know it will direct them to a some kind of product or service that you have to buy as there is no reason why you will spend money on advertising unless you gain something out of it. Another reason can be they know that if they click on the Ad it will add some revenue to the website/blog owner. Also most of the time you might have bad experiences by click to funky attractive banners.
One main category which falls into this category is Computer gigs. They always looking for free stuff and they know how to get it from Google search or any other way. They know how to filter content from Ads. They always try to skip the Ads even though Ads are base on the content.
At the end of day it is just another Ad.
I think it is really important to select a topic that target group of people who is excited about links and banners. According to my experience I think this is a major factor but that doesn't mean that you should stop blogging or creating web on such topics.
