A way to increase the click through rate of your Google Adsense ads is to use the same font that the ads are using on your website. The first problem that you encounter when you want to do that is to find a way to reveal the font that the Adsense units are using. This is actually not a huge problem and can be solved easily. I would like to explain how you would find out information about the font of the Google Adsense unit that you would like to use.

I’m using Firefox for this purpose. Locate an Adsense unit and right-click it. Select This Frame from the menu and View Frame Source. This will load a text file with the source of that frame only. Some CSS knowledge could be helpful now:

…
a:link,a:visited,a:hover,a:active{color:#970009;cursor:pointer;}
body{background-color:transparent;font-family:arial,sans-serif;height:100%}
…
.adt{font-size:11px;font-weight:bold;line-height:14px;}
.adb{color:#000000;display:block;font-size:11px;line-height:14px;}
.adu{color:#000000;font-size:10px;
line-height:12px;overflow:hidden;white-space:nowrap}
.adus{cursor:pointer;}</strong>
…

Lets find out what this code is telling us. We know that each Google Adsense unit consists of three relevant parts that can contain information about the font: the title, the body and the url.

Adsense ad unit title:

a:link,a:visited,a:hover,a:active{color:#970009;cursor:pointer;}
.adt{font-size:11px;font-weight:bold;line-height:14px;}

This line gives us information about the title of the specific ad unit. It has a font size of 11px, a font-weight that is bold and a line height of 14px. The links on your website that are shown near the ad unit should look a like to increase click through rate.

Since the title is a link it uses the a: information as well which set the color of the link to #970009

Adsense ad unit body:

.adb{color:#000000;display:block;font-size:11px;line-height:14px;}
body{background-color:transparent;font-family:arial,sans-serif;height:100%}

The font size of the body is 11 pixels only which is less than the title uses, it has a line height of 14 pixels and uses the font color #000000. The font family for the complete ad unit is arial, sans-serif.

Adsense ad unit url:

.adu{color:#000000;font-size:10px;line-height:12px;overflow:hidden;white-space:nowrap}
.adus{cursor:pointer;}

The color of the url is defined here. Please note that it is also a link but it can have a different color than the title. This here has a color of #000000 which is black, a font size of 10pixels and a line height of 12 pixels.

Those information are valid for a medium rectangle Adsense unit with 4 out of 4 ad spaces occupied. Different ad units do use different fonts and settings. Even the same ad unit uses different font settings depending on the number of ads shown.