levo - 6:21 pm on Jun 30, 2013 (gmt 0) [edited by: martinibuster at 10:59 pm (utc) on Jul 1, 2013]
You can select the asynchronous code for existing ad units.
This help page has example code
@MrSavage It says that because the new code doesn't block page loading, you can see "a noticeable difference on mobile browsers"
[edit reason] Fixed URL. [/edit]
[edited by: martinibuster at 10:59 pm (utc) on Jul 1, 2013]