Imagine, if you will, the first time a billboard went up.  People must have stopped and stared at the enormous advertisement, regardless of what shoddy or excellent product it featured.  And now, Google’s giving you the opportunity to do the same sort of thing with AdSense ad units.

Font sizes labeled “small,” “medium,” and “large” are all available for advertisers to use as they see fit.  The default size is medium, which is actually a bit bigger than what most people are used to seeing, and may therefore yield better results.

Or you can opt for the small size and make users feel a little less pressured to click.  Or just throw caution to the wind and see how users react to the large size.  Google won’t hold you to whatever adjustments you make, so it’s always possible to switch things back or micromanage.

In fact, a post on the Inside AdSense blog points out to readers that they can make changes “on an account-wide basis or by individual ad unit — just follow the instructions listed in our Help Center. . . .  [W]e recommend testing these new font size options with your existing customizations to determine which combinations perform best on your pages.”

So see if you can make people stop and gawk at (and click on) any ads on your site.  At least until the novelty wears off, there’s likely some extra money to be made.