I certainly would never fault anyone for trying to earn revenue with a website they have. If you've created and maintain a website that people find useful then by all means try and monetize it. My sites were up and running and had a few thousand members before I ever even considered making money from YPN or AdSense... I think it is more rewarding to run a website that thousands of people find useful and fun than it would be to throw up some made-for-ads sites. I always think of my audience (visitors) first, then I think of how what I've done can earn some money. But I find it interesting to hear from publishers that are maintaining dozens of low-traffic, low-content sites and earning lots of revenue from the sheer volume of sites.
i've done my own testing and concluded that removing borders and blending ads are a terrible way to increase ctr. what it does increase is banner blindness. if your aim is to get unsolicited user clicks, then by all means, remove the border and slap some images next to them.
I design all of my websites / blogs with the visitor in mind by ensuring quality content is included. Ads, i.e. Google Adsense, is lower down the list of priorities.
I try to make my site for users rather than ads, returning visitors is ultimately the greatest source of revenue .. my 2 cents