Google AdSense has been testing different fonts and has found that various fonts fare better than others depending factors such as size and character width. As a result, they are planning a font face update. Here's what to expect:
Arial: 728x90, 336x280, 120x600, 120x240
Verdana: 300x250, 160x600, 468x60, 250x250, 234x60, 125x125, 180x150
Times New Roman: 200x200
The changes only affect ad units in Latin-based characters and only ads that have been set to "AdSense default" for the font face. The AdSense team recommends conducting your own testing once the changes are in place, in order to get the best performance for your site.
What do you think of the font face changes in AdSense? Tell us in the comments.