A couple months back I was talking to Scott Hanselman and the coversation about blogs and advertising through Google AdWords came up. As you can see, both Scott's blog and mine both don Google AdWords. Anyway, I mentioned that the results were pretty pitiful, and Scott suggested that I take the ads and make sure that the background color and link color of the ads was the same as the background color and link color where they appeared on the page. In other words, don't use a different background color and link color to “offset” the ads; rather, make them look like part of the normal page.
Rather than just take his word on it, I decided to setup a little experiment. I have two Google Ads on my blog - one in the left hand column, shown on all pages except when viewing a post, and the other when viewing a post, wedged between the blog content and where the comments begin.
The left hand column of my blog has a white background. To test Scott's hypothesis about having the same background color, over the past six weeks or so I've randomly display the ads with either a white background or a dark gray background (matching the center column's background color). The results? Scott was right on the money: the white background had five times as many click throughs as the dark gray background. (Don't get too excited, we're talking about making enough per day now to buy a cup of coffee, versus making enough to buy a pack of gum. But still, no complaints, I'll take it.) As you may have guessed, I've now ended my experiment - all ads shown on the left column now have a white background.
The other test I ran was when viewing a particular blog post. For that ad section I kept the background color of the ads the same color as the actual background (dark gray), but varied the link color, using black links for one and blue links (the actual link color on my blog) for the other. The results? The click throughs were nearly identical; while the black link test had a very slight increase in click throughs, I doubt the increase is statistically significant.
So if you run your own site using AdWords, consider making the ad background color the same background color of your site so that the links blend in instead of standing out. With any luck, you'll see your click throughs increase several times over as well.