Google AdSense official blog had announce that now the site owner can customize the font face for Google AdSense ad unit. This is a great news for all of the webmaster because now you have more flexibility when you design the ad to be place in your website.
“However, you can also select custom font faces for specific ad units that you’ve created with the Manage Ads feature. When creating new ad units, you’ll be prompted to select between the default ‘Standard AdSense font family’, your new account-wide font face (if you’ve selected one), or another font face. You can also change the appearance of existing ad units, by visiting the Manage Ads page of your account and updating your font choices for specific ad units. Once you’ve changed the font face of an ad unit away from the default, those selections will be maintained even if you change your account-wide settings later.”
Click here to read more detail